Well over a month ago, my husband spotted a Reese’s peanut butter cup-inspired cake on Reddit entitled something like, ‘I went away for two days and look what my girlfriend made for me’. This cake had it all. Gooey, glossy chocolate fondant dribbling down the sides, peanut butter cups decorating the top, and a luscious-looking peanut filling. The works. Not to be outdone by a total stranger on the internet, I decided that a peanut butter cup cake would be just the thing for the surprise birthday party I had planned for him.
I started sketching up designs for the cake (yes, I actually did this) and set to work finding the best recipes for chocolate cake, peanut butter icing, chocolate ganache and fudge. I eventually settled on this very dense chocolate cake recipe at Dana’s recommendation, and a peanut butter mousse recipe borrowed from Dana’s Heaven and Hell Cake. What I ended up with was a very rich, dense chocolate cake, sandwiched with peanut butter mousse, wrapped in salted peanut fudge, topped with chocolate ganache. It is the single most decadent thing I have ever made, but in the interests of full disclosure it did take me the whole day.
- 2 cups all-purpose flour
- 1 teaspoon salt
- 1 teaspoon baking powder
- 2 teaspoons baking soda
- 3/4 cup unsweetened cocoa powder
- 2 cups sugar
- 1 cup vegetable oil
- 1 cup hot water
- 1 cup milk
- 2 large eggs
- 1 teaspoon vanilla
- 90ml Double cream
- 1 cup smooth peanut butter
- 170g cream cheese
- 110g icing sugar
- 150g chocolate
- 140 grams double cream
- A tablespoon golden syrup, if required
- 200g condensed milk
- 60g butter
- 225g Soft brown sugar
- 75ml milk
- Few drops vanilla essence or other flavouring
- A handful of crushed peanuts
- Make the chocolate cake: Preheat the oven to 160°C (325°F). Mix together the dry ingredients, and in a separate bowl, whisk together the oil, hot water and milk. Add to the dry ingredients, then beat in the eggs and vanilla. Be warned, this will be very runny.
- Pour into a deep 22cm (or 9-inch) round cake tin and bake for 50 mins to 1 hour. The cake will be much gooier than a sponge so won’t be as springy to the touch when it’s done - it’s done when a skewer comes out clean. Cool it in the pan for a few minutes, and then transfer to a cooling rack to cool completely.
- Make the peanut butter mousse: In a large bowl, beat cream cheese, peanut butter, and confectioners’ sugar with a handheld mixer on medium speed until smooth and fluffy. Put the cream into a large bowl and beat on high speed until stiff peaks form. Using a rubber spatula, fold the whipped cream into the peanut butter mixture; set mousse aside in the refrigerator.
- Make the fudge: You’ll need a sugar thermometer for this part. Put the butter into a pan and melt it. Mix in the sugar, milk and condensed milk. Turn up to a medium heat and get the fudge mixture to ‘softball’ temperature - 115°C (240°F) before removing from the heat.* Stir continuously, or it will burn. Pour the mixture into a new bowl (or the heat from the pan makes it hard to cool the fudge) and beat the mixture until it is grainy and has completely lost its gloss, but is still pliable. This will take at least ten minutes. Be patient.
- Smooth the fudge out onto a layer of plastic wrap, and place another layer of cling film on top. Roll the fudge out so that it is twice the height of your cake, and half of the circumference. Take off the top layer of cling film, and sprinkle on the crushed peanuts, pressing them in slightly. Leave to cool completely.
- Make the ganache: I followed a recipe that was not a 100% complete success. I suspect I heated the cream a little too much, as the fat separated from it and left a sort of oily residue on the ganache, which went a little opaque in the fridge. It tasted fine, but didn't look as glossy and delicious as I imagined it would. I think the take-home message is to just warm the cream - don’t let it get too hot!
- Warm the cream and pour in the chopped chocolate, letting the heat of the cream melt the chocolate. If the texture is a little grainy, you can beat in some golden syrup to smooth it out. Put a few spoonfuls of the ganache into a piping bag and chill it slightly - leave the rest just to cool to room temperature.
- Assemble the cake! First of all, cut the cake in half through the middle. Take the top slice and use it as the bottom of the cake, ensuring a nice flat top to the cake. Slather liberally with peanut mousse. TRY NOT TO EAT ALL OF THE PEANUT BUTTER MOUSSE. Put the two halves of the cake together, and then spread a little of the mousse onto the sides of the cake to help hold the fudge in place.
- Pipe your chilled ganache around the top of the cake at the edge - this wil l stop your runny room temperature ganache from spilling over the sides. Spread the remaining ganache over the cake from the middle outwards, and try to work it as little as possible as you will only end up picking up crumbs from the cake. Spread it on like you would nail polish - as few strokes as possible.
- Next, slice the fudge in half length ways so that you have two long strips the same size as the height of your cake. Place peanut-side down on some cling film to help you hold on to it so you can wrap it around the side of the cake. I found this was actually a two man job, and got a friend help hold onto it as I lifted it into place! Once the two pieces of fudge are wrapped around the cake, press the ends together gently, and press the fudge into the cake a little to secure it. Leave in the fridge for 30 mins if you are worried it won’t hold in place.
- Serve up to your guests, and watch an entire day’s work disappear within about ten minutes. Enjoy!
- *If you don’t have a sugar thermometer, you can test this by dropping a piece of mixture into a glass of cold water. If it forms a soft, pliable ball rather than a runny mess, you’re there. This will take around 10 mins of bubbling away. Nonetheless, this is a very imprecise way of doing it and runs a far greater risk of scalding yourself. A kitchen thermometer that goes to a high range is about £15 / $25 USD and a very worthwhile investment.
What I’m Drinking:
I am drinking Jura ten year old whiskey, because it was a gift at the party the cake was made for and oh that stuff is delicious.
What I’m Listening To:
I’m listening to a lot of Iron & Wine at the moment (perfect calm time music as essay season approaches…).Add to favorites