Nigella’s Peanut-Butter Squares for the base:

50g dark muscovado sugar 200g icing sugar 50g unsalted butter 200g smooth peanut butter for the topping:

200g milk chocolate 100g plain chocolate 1 tablespoon unsalted butter 1 x 23cm square brownie tin Stir all the ingredients for the base together until smooth. Use either a bowl and a wooden spoon or the paddle attachment on the mixer. You will find, either way, that some of the dark muscovado sugar stays in rubbly lumps, but don’t worry about that. Press the sandy mixture into the lined brownie tin and make the surface as even as possible. To make the topping, melt the chocolates and butter together (in a microwave for ease - for a minute or two on medium) and spread on the base. Put the tin in the fridge to set. When the chocolate has hardened, cut into small squares - because, more-ish as it is, it is also very rich.