01 - Preheat oven to 350°F. Line a 12-cup muffin tin with paper liners.
02 - Whisk together flour, baking powder, baking soda, and salt in a medium bowl. Set aside.
03 - Beat butter and sugar with an electric mixer until light and fluffy, about 2-3 minutes.
04 - Beat in eggs one at a time, mixing well after each addition.
05 - Mix in vanilla and mint extracts. Add green food coloring and mix until evenly tinted.
06 - Alternately add dry ingredients and milk to the butter mixture, starting and ending with dry ingredients. Mix until just combined.
07 - Divide batter evenly among cupcake liners, filling each about 2/3 full.
08 - Bake for 18-20 minutes, or until a toothpick inserted in the center comes out clean.
09 - Cool cupcakes in the tin for 5 minutes, then transfer to a wire rack to cool completely.
10 - Beat butter until creamy. Gradually add powdered sugar on low speed. Add mint and vanilla extracts, green food coloring, and 2 tbsp milk. Beat until fluffy, adding more milk if needed.
11 - Pipe or spread frosting on cooled cupcakes. Garnish with green sprinkles or a maraschino cherry if desired.