Set aside 50g each of the peanut butter and chocolate. Heat oven to 180C/160C fan/gas 4 and line a 20cm square baking tin with baking parchment. Gently melt remaining peanut butter, chocolate and all the sugar in a pan, stirring occasionally, until the sugar has just about melted. Transfer mix into a bowl to cool down slightly. Turn off heat and use a wooden spoon to beat in the eggs one by one. Stir in the flour and scrape into the tin.
Walnut Cupcakes with Maple Frosting
Ingredients:Cupcakes:½ cup granulated sugar½ cup packed brown sugar6 tablespoons butter, softened3 large eggs1 teaspoon vanilla extract8 ounces cake flour (about 2 cups)½ teaspoon baking soda¼ teaspoon salt¼ teaspoon ground cinnamon½ cup buttermilk⅓ cup plus 2 tablespoons walnuts, toasted, chopped, and dividedFrosting:½ teaspoon cream of tartar3 large egg whites¾ cup maple sugar or granulated sugar¼ cup…