Chocolate & Walnut Butter Fudge Cake

This recipe started out being a conversion of a wheat based recipe that appeared in the June edition of delicious. magazine by master French patissier Jean Michel Raynaud. It sounded a wonderful cake - chocolate, walnuts, butter, fudge & it was topped off with a caramel sauce. Fantastic!

My first attempt at making the cake gluten free was a dee-zas-ter. I even followed the instructions (mostly) but made some allowances for using Bakers' Magic Gluten free flour. My kitchen was awash with bowls (just a little exaggeration). Basically I had to separate the eggs, beat caster sugar with the whites & honey & demerara sugar with the yolks. Carefully fold softened butter into melted chocolate (it can't be too hot otherwise you'll melt the butter). Then fold these two together, then these two together, then these two together & put it into two loaf tins & bake for ~50 mins. The cakes rose & rose & rose until I thought they were going to overflow my baking tins. When it cooled they flopped - no it wasn't just a flop it was like a huge gaping sink hole appearing in my Chocolate & Walnut Butter Fudge cake.  

I & my family tasted my flopped cake.....

  • lemon - yes
  • walnuts - yes
  • butter - yes
  • chocolate - no
  • fudge - yes

It is simple, we wouldn't describe it as a chocolate cake. Maybe a walnut & lemon cake - my daughter's words. 

Okay - back to the drawing board.

So I made a wheat flour version of the cake. Two things I changed in the recipe - I substituted in dark chocolate instead of milk chocolate & I used salted butter instead of unsalted butter. I also followed the instructions. 

Guess how it turned out.

I took a photo on my phone because..... 

it flopped too.

For comparison purposes I have to include a photo of the cake as it appeared in delicious. magazine.

Their cake looks great & nothing like mine (apart from the walnuts :) ).

Next I made a scaled down melt 'n mix gluten free version & baked 3 Texan muffin sized cakes. I did add a bit more chocolate & a bit more flour - they deflated a bit but nothing like the earlier versions. In a muffin tin the cake batter is supported by the sides more so than in a cake tin. Basically I had to try & make the cake again but in the tin that was suggested in the original recipe.

Making a cake using a melt 'n mix method is a lot easier to do than separating the egg whites & yolks, beating them & folding, folding & folding. Separating the eggs, beating them separately & folding together will create a lot of aeration in the batter. Hopefully when the wheat flour is finally folded in there is not a great deal of deflation & that gluten structure hasn't developed. This should result in a beautifully light wheat based cake.

But the thing is we are not using a wheat based flour. When using Bakers' Magic Gluten free flour water & fat needs to be added to develop the strength that comes from the protein & fibre in the mix. Other gluten free mixes may behave differently. The only water in the recipe is that in the eggs & butter. Water in the latter becomes available if the butter is melted. For this recipe a melt 'n mix method may be a good way to make the cake batter.

Unfortunately the cake still flopped.  

My dilemma was this; Do I convert the recipe into a workable walnut butter fudge cake knowing that the chocolate flavour is not strong or do I change the recipe so that it is a chocolate walnut butter fudge cake?

I decided to do both.

First up is the conversion of the delicious. magazine's recipe. The original recipe made two cakes but used 4 eggs + 5 extra yolks - I have cut it down to make 1 cake. 

delicious. magazine version

Ingredients

Cake

150 g Bakers' Magic Gluten free flour

100 g Water (hot)

3 Whole eggs

4 Extra egg yolks

337 g Butter (melted)

100 g Demerara sugar

55 g Honey

258 g Caster sugar

135 g Dark chocolate (original was milk)

187 g Walnuts (roughly chopped)

Zest of 1/2 lemon

 

Caramel

100 g Cream

200 g Caster sugar

150 g Butter (softened)

~100 g Water

2 tsp Vinegar#

 

Vinegar was not put in the original recipe. I put it in to help stop the sugar from crystallising.  

Method

Turn oven on to 160 C.

Grease a cake ring tin.

Cake

If you keep your eggs in the fridge 1/2 fill the kitchen sink with hot tap water. Put the eggs in the hot tap water for 10 mins. If you keep your eggs at room temperature warm the eggs up by placing them in a dish of warm water (slightly hotter than 37 C).

Put the Bakers' Magic Gluten free flour in a mixing bowl from a stand mixer (or large bowl if using hand held beaters).

Melt the butter.

Add the hot water to the butter & then the 3 whole eggs & 4 yolks. Briefly whisk with a fork.

Pour the wet ingredients over the Bakers' Magic Gluten free flour & mix until there are no lumps in the batter.

Add in the sugars, honey & lemon zest.

Melt the chocolate. Microwave or stove top is fine. 

Add in the chocolate & beat for ~5 mins.

Add in the chopped walnuts & pour into the cake tin. 

Bake for ~1 hour, insert a skewer close to the time to see if it is ready. If the skewer comes out clean take the cake out of the oven. During this time the cake will rise considerably & will deflate when it is out of the oven. 

Allow to cool for 15 -20 mins before turning the cake onto a serving plate.

The original recipe was baked in a loaf tin & the top was cut off before putting on the caramel sauce. I liked the contrast between the fudgy interior & the crust as such I didn't cut off any of the cake. 

The cake batter is not dense enough to keep the walnuts in suspension in the middle of the cake. Most of them will sink down to the bottom, the bottom will become the top when the cake is turned out of the tin. 

Caramel

Heat the cream to just below boiling point & then set aside.

The next step involves making a toffee base for the caramel. If you have not made toffee/caramel before there are some great tips found on David Lebovitz's website.

Put the sugar into a heavy based saucepan with the water. Gently heat to dissolve the sugar without boiling it, at this stage you can stir the mixture. While stirring try not to get any sugar on the sides of the pan. When the sugar is dissolved turn up the heat & boil for ~5-10 mins until it is golden brown. Do not stir the sugar mixture when it is boiling (don't even swirl the saucepan)- if you do the sugar will crystallise & instead of caramel you will end up with fudge. The time required for boiling will depend on the heat used & the colour of the sugar syrup. The syrup can quickly burn so when the sugar syrup starts changing colour reduce the heat a little & do not take your eyes off the syrup.   

When the syrup is the colour you want carefully pour in the cream & stir well for ~1 minute. There will be a lot of steam generated so take care. 

Take off the heat & stir in ~1/4 of the softened butter. When it is incorporated into the sauce add in another ~1/4. Repeat until there is no more butter left. 

The dark brown caramel pictured below was burnt. Looks dark & delicious but tastes burnt, beautifully smooth but still burnt. Picture my daughter's face when her "lovely" big brother gave her a teaspoon of mum's latest caramel. The other caramel was silky smooth & oh so delicious - the "lovely" big brother didn't give any of that caramel away. 

The second time I made the caramel I swirled the saucepan - I know, I know you're not supposed to swirl the pan. So I ended up with crystallised caramel (fudge). The thing is it usually starts to crystallise when it is reasonably cold so I didn't realise that it was going to do that until it was too late - I'd already poured it on the cake. As a fudge it is still delicious but not as smooth as the caramel. 

Next time if my caramel starts to crystallise I would turn it into fudge by;

  • Line a small pan with baking paper
  • Add in a bit of vanilla essence to the "caramel"
  • Half fill the sink (or a large bowl) with cold water
  • Put the saucepan into the water
  • Using a wooden spoon beat the mixture until it starts to thicken
  • Transfer the mix to the small pan
  • Make the indentions for small squares when still slightly warm

If your toffee burns throw it out & start again.

One version down & one to go.

The version I made had two cake layers sandwiched with caramel/fudge & then encased in a chocolate shell. A bit over the top but delicious. The chocolate shell reminds me of the interior of Lindor balls - very rich but very moreish. If you don't want to put the chocolate shell on simply sandwich the cakes together with the caramel & pour it over the top of the cake.  

Libby's Chocolate & Walnut Butter Fudge Cake

Ingredients

Cake

175 g Bakers' Magic Gluten free flour

55 g Water (hot)

5 Eggs

300 g Butter (melted)

100 g Demerara sugar

75 g Honey

250 g Caster sugar

250 g Dark chocolate

200 g Walnuts (roughly chopped)

Zest of 1/2 lemon

 

Caramel

100 g Cream

200 g Caster sugar

150 g Butter (softened)

~100 g Water

2 tsp Vinegar#

 

Vinegar was not put in the original recipe. I put it in to help stop the sugar from crystallising.

 

Chocolate Shell

350 g Good quality milk chocolate

250 g Unsalted butter (softened)

 

Method

Turn oven on to 160 C.

Line two 20 cm round cake tins with baking paper.

Cake

If you keep your eggs in the fridge 1/2 fill the kitchen sink with hot tap water. Put the eggs in the hot tap water for 10 mins. If you keep your eggs at room temperature warm the eggs up by placing them in a dish of warm water (slightly hotter than 37 C).

Put the Bakers' Magic Gluten free flour in a mixing bowl from a stand mixer (or large bowl if using hand held beaters).

Melt the butter.

Add the hot water to the butter & then the 5 eggs. Briefly whisk with a fork.

Pour the wet ingredients over the Bakers' Magic Gluten free flour & mix until there are no lumps in the batter.

Add in the sugars, honey & lemon zest.

Melt the chocolate. Microwave or stove top is fine. 

Add in the chocolate & beat for ~5 mins.

Add in the chopped walnuts.

Divide the mixture between the cake tins. 

Bake for ~40 mins, insert a skewer close to the time to see if it is ready. If the skewer comes out clean take the cake out of the oven. During this time the cakes will rise considerably & will deflate when they are out of the oven. 

Allow to cool for 10 mins before removing the cake from the pans.

Let the cakes cool before assembling with the caramel & chocolate. I put my cakes outside to cool down - it was 6 degrees.

I levelled the tops of the cakes (a little) to make them "even" before sandwiching them together.

Caramel

Heat the cream to just below boiling point & then set aside.

The next step involves making a toffee base for the caramel. If you have not made toffee/caramel before there are some great tips found on David Lebovitz's website.

Put the sugar into a heavy based saucepan with the water. Gently heat to dissolve the sugar without boiling it, at this stage you can stir the mixture. While stirring try not to get any sugar on the sides of the pan. When the sugar is dissolved turn up the heat & boil for ~5-10 mins until it is golden brown. Do not stir the sugar mixture when it is boiling (don't even swirl the saucepan)- if you do the sugar will crystallise & instead of caramel you will end up with fudge. The time required for boiling will depend on the heat used & the colour of the sugar syrup. The syrup can quickly burn so when the sugar syrup starts changing colour reduce the heat a little & do not take your eyes off the syrup.   

When the syrup is the colour you want carefully pour in the cream & stir well for ~1 minute. There will be a lot of steam generated so take care. 

Take off the heat & stir in ~1/4 of the softened butter. When it is incorporated into the sauce add in another ~1/4. Repeat until there is no more butter left. 

Let the caramel cool before using, you don't want it runny but you don't want it solid either.

Putting it together

Put the bottom cake right way up on a serving plate.

Spread the caramel on top of the cake.

Invert the other cake & place it on the top of the caramel. If you want put a layer of caramel around the outside of the cake. 

Chocolate Shell

For the chocolate shell it is best if the chocolate is melted in a bowl over a saucepan of hot water. Basically you have better control of the temperature of the chocolate as the softened butter needs to be folded into the melted chocolate without the butter melting. When the butter melts the water present becomes available & will essentially seize the chocolate. Seized chocolate is grainy, has no gloss & would not make a good shell. If the chocolate seizes start again with fresh chocolate.

Leave the butter at room temperature to soften. 

Put 1/2 - 2/3 of the chocolate in a stainless steel bowl. Place on top of a saucepan containing hot water. Gently melt the chocolate. Take the bowl off the heat & add the remaining chocolate. Stir the chocolate until it is all melted.

Add ~1/4 of the butter to the chocolate & fold it in. If the butter is soft enough it will be easy to put blobs of it into the chocolate. I didn't use a thermometer but if you have one it might be a good idea to use it. If the temperature of the chocolate is above 32 degrees the butter will start to melt.

Add more butter to the chocolate & continue folding it in until there is no butter left.

The chocolate butter needs to cool down before putting it on the cake.

The length of time needed for the chocolate to cool down will depend on the temperature of the room (or the temperature outside). Stir the mixture every now & then to stop the chocolate setting on the sides of the bowl.  

Encase the cake with the chocolate butter. Let the shell harden before trying the cake. 

How much caramel & chocolate shell you put on the cake is up to you.

Enjoy!