Method

1. Preheat oven to 350 degrees (175 degrees C) and line 12 muffin tins with paper cupcake liners.
2. In a large bowl sift together the flour, baking powder, salt, and cocoa powder.
3. In the bowl of your electric mixer, or with a hand mixer, beat the butter until soft (about 1-2 minutes). Add the sugar and beat until light and fluffy (about 2-3 minutes). Add the egg and beat until incorporated. Scrape down the sides of the bowl. Add the vanilla extract and beat until combined.
4. In a measuring cup whisk the buttermilk with the green food colouring. With the mixer on low speed, alternately add the flour mixture and buttermilk to the butter mixture, in three additions, beginning and ending with the flour.
5. In a small cup combine the vinegar and baking soda. Allow the mixture to fizz and then quickly fold into the cake batter.  Working quickly, divide the batter evenly among the 12  muffin cups and smooth the tops with an offset spatula or the back of a spoon.
6. Bake in the preheated oven for approximately 18 – 23 minutes, or until a toothpick inserted in the centre of the cupcakes comes out clean.
7. Cool the cakes in their pans on a wire rack for 10 minutes and then remove them from the pan. Let cool completely before frosting.
8. Either spread the frosting with a knife or offset spatula or use a large 1M Wilton open star decorating tip to pipe the frosting.

Cream Cheese Frosting:

1. In the bowl of your electric mixer, or with a hand mixer, beat the cream cheese until smooth.
2. Add the vanilla and confectioners sugar and beat until smooth.
3. Using the whisk attachment, gradually add the heavy cream* (See Note) and whip until the frosting is thick enough to pipe.
4. Add more sugar or cream as needed to get the right consistency.

Note: You must use a brand of heavy cream that whips very easily to stiff peaks. If you are using a brand of heavy cream that does not whip easily to stiff peaks then whip the heavy cream separately to stiff peaks and then fold it into the cream cheese mixture.