Chocolate Peanut Butter Cup Cheesecake

There are a few things that I am finding quite perplexing lately...

Step 1 - Why Justin Bieber and Miley Cyrus are so popular (then again I'm out of their fan age group).

Step 2 - Why people chew gum. It only makes me hungry and it loses its flavour after about five minutes.

Step 3 - How Rachel Zoe and Victoria Beckham can get pregnant given that they probably live on about 500 calories a day.

Step 4 - Why drivers in Sydney drive right up to your rear bumper even if you are sticking to the speed limit.

Step 5 - Why on the only time that I've accidentally sat on the iPad, Mr NQN sees me doing it. He is now convinced I sit on it all the time and that I will soon break it...

One thing that doesn't stump me however is the peanut butter and chocolate combination. Some wrinkle their nose at this combination but I have an avowed love of Reese's peanut butter cups and Lindt's peanut butter Lindor balls. I have even tried making the peanut butter cups from scratch as well as a bannoffee flavoured peanut butter cup.

I first saw the idea on Julie's lovely blog Willow Bird Baking and thought that it was a fantastic idea for a cheesecake flavour. My friend Nic had made a version from Nigella's new book and said that it wasn't nearly peanut butter cup enough and questioned whether it was worth the calories-and that's never good. To me the key to the peanut butter cup is the slight saltiness from the peanut butter and the milk chocolate. You could of course use dark chocolate but it will miss out on that unmistakeable peanut butter cup taste.

I experimented with a couple of cheesecakes giving the final completed one to friends Gina and Teena for their joint birthday dinner at La Casa. In it I submerged some Lindor peanut butter balls and then another layer of milk chocolate mousse draped over the top using Julie's recipe. It was rich, that much is for certain but I was happy that it replicated the peanut butter cup experience. Even Philippe who couldn't comprehend the idea of a peanut butter and chocolate cheesecake liked it although he was sighted afterwards looking still quite perplexed at why he had liked something that he still couldn't quite understand.

So tell me Dear Reader, is there anything perplexing you lately?

Chocolate Peanut Butter Cup Cheesecake

An original recipe by Not Quite Nigella (mousse adapted from Willow Bird Baking)

Crust

• 280 g/10 ozs chocolate biscuits (chocolate peanut butter if you can find them) blitzed in food processor until fine

• 85 g/3 ozs melted butter

• 50 g/1.5 ozs milk chocolate flakes

Filling

• 750g/26.5 ozs cream cheese

• 4 eggs

• 1/2 cup caster sugar

• 200g/ 7 ozs smooth peanut butter

• 2/3 cup milk chocolate chips

• 1/2 teaspoon plus a pinch of salt

Mousse topping

• 1 sheet titanium strength gelatin leaf

• 1 cup heavy cream

• 2 large egg yolks

• 1 1/2 tablespoons sugar

• 50g/1.5 ozs milk chocolate, chopped

• 10 Lindor peanut butter balls or Reese's peanut butter cups plus extra to decorate

Step 1 - Preheat the oven to 160C/320F and find a baking tray that will fit your 22cm springform tin in so that you can make a water bath for the cheesecake that goes halfway up the cake. For the crust, mix the butter and  and up the sides of a 22cm springform pan. Sprinkle milk chocolate flakes on the bottom. Set aside in the refrigerator.

Step 2 - Put a kettleful of water on the boil. In the cleaned food processor beat the cream cheese and sugar until smooth. Add eggs one at a time and the peanut butter and beat until smooth but do not overbeat.

Step 3 - Take out the biscuit base. Put 2 layers of foil around the tin to prevent any water from the water bath from getting in. It’s useful to have that wider foil for this task if you have it. I didn’t and it was still ok though.

Step 5 - Place tin in a deep baking dish and pour the cream cheese filling into the foil lined tin. Submerge the Lindor balls or Reese's peanut butter cups into the cheesecake. Then pour the boiling water from the kettle around the cheesecake so that it sits in a bath being careful not to splash any on the cheesecake itself.

Step 6 - Carefully transfer to the oven and bake for 1 1/4 hours although you may want to check at 1 hour. The outside should be set and the inside with a hint of wobble which will firm up in the fridge. Remove the foil and cool on a wire rack and when cold, place in the fridge overnight covered with clingfilm.

Step 7 - For chocolate mousse, dissolve the gelatin in a small bowl of cold water and let stand for 5 minutes until it soft and pliable-squeeze out any excess water. In a saucepan over moderate heat, cook the cream until it bubbles around the edges. In another bowl, whisk together egg yolks and sugar. Temper the eggs: pour about 1/2 cup hot cream into the egg yolks slowly while whisking vigorously. Then slowly pour the egg mixture into the saucepan of cream (whisking constantly) and add chocolate. Cook over low heat, stirring constantly, until thickened, about 3 minutes. Remove from the heat and whisk in the gelatin. Place mixture into a wide bowl to allow it to cool for a bit, then chill it for just a little while — not until set, but until it’s not so runny. Pour the mixture onto the top of the cheesecake and refrigerate at least one hour or overnight. Decorate with chopped Reese’s cups, if desired.