Instructions

1. Preheat oven to 180 C (350 F) standard / 160 C (320 F) fan-forced. Line a 12 hole muffin tin with cupcake liners.
2. In a large mixing bowl, add flour, cocoa powder, baking soda, baking powder and then add the sugars. Pop the butter into the microwave for a short burst, 10 seconds or so at a time, until it becomes very soft but just before it is completely melted. Give it a stir with a fork to eliminate any lumps.
3.  In a separate mixing bowl, add eggs, vanilla and butter and whisk together until smooth. Then add the wet mixture into the dry mixture, along with the buttermilk and gently fold until just combined.
4. Spoon the mixture into the cupcake liners and pop into the oven. Bake for 18-20 minutes or until just cooked through. Set cakes out onto a wire rack and leave to cool completely.
5. In a large mixing bowl, add the butter and peanut butter and beat with an electric mixer until smooth and creamy. Add the icing sugar, one cup at a time, and continue to beat. Add a tablespoon or two of milk to help loosen up the mixture. Continue to add a tablespoon of milk as needed. The icing should be nice and creamy but thick enough to hold its shape.
6.  Pipe the frosting onto the cupcakes using a piping bag and a large round tip. Warm a little extra peanut butter in the microwave, just until smooth. Drizzle a little peanut butter on top of each cupcake and then sprinkle a few chocolate chips on top.