Preheat the oven to 350°F. Line a cupcake tin with paper liners, set aside.
Whisk together the flour, cocoa powder, baking soda, baking powder, and salt into a medium-sized bowl, set aside.
Pour the butter into a large bowl and add the sugar, stir together until combined. Add the egg and stir in until combined. Add the vanilla and vinegar, stir to combine.
Add the flour mixture (a little at a time) and stir it in until fully combined with no dry patches.
Add the buttermilk, stir until combined.
Scrape down the sides well and add the food coloring until everything is dyed green.
Fill the liners evenly, a little more than ¼ cup batter into each cupcake liner. Bake for 15-18 minutes until a toothpick inserted into the center comes out clean.
Let cool in the cupcake tin for 5 minutes. Place cupcakes on a wire rack to cool completely.
Add frosting of your choice!
I am using cake flour in this recipe. You can find it in the baking aisle of your grocery store. One of the more popular brand names for cake flour is "Swans Down." I have started experimenting with this flour in my baked goods and I really think it makes a difference in how fluffy it turns out. If you can't find it, you can use all-purpose flour. Just sift it before using.
The difference between cake flour and all-purpose flour is cake flour is made with a soft winter wheat grain and is very finely milled. The protein content is also lower than all-purpose flour which means it produces less gluten. So you end up with a lighter, fluffier and less dense baked good.
I am also using gel food coloring. The same one I used for my RICE KRISPIES CHRISTMAS WREATHS. The color is called "Kelly Green" and it produces a deeper green flavor than the bottled liquid food coloring. If you can't find gel food coloring, then you will probably need to use an entire bottle of green food coloring to produce the same results.
I also recommend buying a small bottle of buttermilk for this recipe. The thick richness of real buttermilk really adds to the moistness of the cupcakes. It's the fat in the buttermilk that we want here.