Mix the flour, granulated sugar, eggs, bicarb and butter together in a mixing bowl. Once smooth, divide between 12 cupcake cases.
Bake in the oven for 20 minutes, till golden. If a toothpick stuck in the centre comes out clean, they're ready.
When the cupcakes are cooling mix about 1 teaspoon of water into the icing sugar until smooth, adding more water if needed (but don't make it too runny).
When the cupcakes are cool spread the icing on top of the cupcakes. Then pile two marshmallow on top of the cake using the icing as glue. Cut the pretzels into quarters and stick two into the marshmallows so they look like arms. Stick on the chocolate chips using icing to look like eyes.
You might need to hold the marshmallows for a couple of seconds so they don't fall down.