Preheat the oven to gas 4 / 180C/ 350°F and line a 12 hole muffin tin. In a small bowl, mix together the flour, cocoa powder, baking soda, baking powder and salt then set aside

Whisk together the milk and the vinegar. Add the Guinness, sugar, oil and vanilla to the milk mixture and beat until foamy

Add the dry ingredients in two batches and beat until well incorporated. Fill your cupcakes containers of choice 3/4 full. Bake for 20-25 minutes, or until a toothpick inserted into the center comes out clean

Let cool completely on a wire rack before topping with a swirl of the chocolate buttercream icing

Roll out the fondant to about 5mm thickness and cut out circles slightly smaller than the tops of your cupcakes. Place on top of the buttercream layer

Dye the offcuts green, roll out again, sprinkle with green edible glitter (not required but looks really good!) and cut out with a small heart cutter. You need 3 hearts per cake, 36 in all, and 12 little 'stalks' - see picture

Arrange on top of the fondant in a shamrock shape and the luck o the Irish be with ye!