Peanut butter and salted caramel cake

Cakes for work have turned into requests recently. It was N's birthday on Wednesday and a cake was required to mark the occasion. Given that she is 

obsessed with salted caramel and love peanut butter also

what could I do but try and incorporate those into a cake? 

I went for layers of peanut butter cake and chocolate cake, sandwiched by a salted caramel and finished with a peanut butter butter-icing.

I'm always worried when I've made a cake to "order" as I just hope it lives up to expectations. Thankfully I think this one did. Remarkably when the e-mail went out to the team a queue formed!

The peanut butter cake was quite subtle which, it turns out, was a good think. The peanut butter hit came from the wondrously rich icing which was offset by the bitter chocolate layer (the chiffon cake that I had previously used for my banana, chocolate and peanut butter cake) and the salty caramel. (I was a bit worried about the salted caramel as it seemed to split slightly as it cooled. It was also terribly difficult to spread.) All the elements worked harmoniously together to give a rather satisfying cake.

Peanut butter and salted caramel layer cake

Ingredients:

For the peanut butter cake (adapted from The Woks Of Life Classic Peanut Butter cake):

145g plain flour

1tsp baking powder

1/2tsp bicarbonate of soda

1/4tsp salt

4tbsp oil

65g smooth peanut butter

84g caster sugar

2 eggs

1/2tsp vanilla extract

118ml buttermilk

For the chocolate cake:

4 eggs
4oz caster sugar
3oz plain flour
1oz cocoa
3tbsp boiling water
2tbsp vegetable oil
1tsp baking powder
1tsp vanilla extract

For the salted caramel (adapted from Felicity Cloake's perfect recipe):

200g white sugar
125ml water
100g butter, cubed
75ml double cream
1tsp sea salt

For the peanut butter icing:
6oz smooth peanut butter
3oz butter
9oz icing sugar

Milk

To decorate:

Reese's peanut butter cups, halved

Method:

1. For the peanut butter cake whisk together the flour, baking powder, bicarbonate of soda and salt and set aside.

2. In a separate bowl beat together the oil, peanut butter, and sugar until smooth. Beat in the eggs one at a time, followed by the vanilla. 

3. Add the dry ingredients to the peanut butter mixture, alternating with the buttermilk, starting and ending with the dry ingredients. Fold it all together gently until smooth.
4. Put the batter into a lined and greased 8" cake tin. Bake for at 180°C for 25-30 minutes at 180°Cor until the cake is done (a skewer comes out clean and the sides are starting to pull away from the tin). Allow to cool.

5. For the chocolate cake, separate the egg yolks and whites. Whisk the egg yolks, sugar, oil, water and vanilla into a smooth batter.
6. Sieve in the flour, cocoa and baking powder and beat until combined.
7. Whisk the egg whites until stiff then fold into the chocolate mixture.
8. Put the batter into a lined and greased 8" cake tin. Bake at 180°C for 40mins or until the cake is done (a skewer comes out clean and the sides are starting to pull away from the tin). Allow to cool.

9. For the salted caramel, put the sugar in a wide, heavy-bottomed pan and pour over the water. Set over a medium heat and keep an eye on it as the sugar melts and begins to brown.

10. Once it turns a deep, but not dark, amber colour, take it off the heat and whisk in the butter until it is completely melted, then stir in the cream and ½ tsp salt.

11. Once you have a smooth sauce, scoop a little up on a teaspoon, allow to cool, and taste for seasoning; add more salt if you like. (Add a little milk if it is too thick).

12. For the peanut butter icing, beat together the peanut butter, butter and icing sugar. Use a milk to get a good consistency.

13. To construct the cake, first halve the two cakes. then sandwich together using a third of the salted caramel (this may be best spread slightly warm). Alternate between chocolate and peanut butter cake layers.

14. Use a small amount of the peanut butter icing as a crumb layer and cover the whole cake. Chill.
15. Generously ice the cake with the remaining peanut butter icing.

16. Decorate with the halved Reese's peanut butter cups.