1-Preheat your oven: Preheat your oven to 350°F (175°C) and line a cupcake pan with paper liners. Measure all ingredients precisely to handle high altitude baking.

2-Whisk dry ingredients: In a large bowl, whisk together the flour, baking powder, and salt to distribute the leavening agents evenly.

3-Cream butter and sugar: In another bowl, cream softened butter and granulated sugar until light and fluffy, then add eggs one at a time, beating well after each.

4-Add flavor and coloring: Mix in peppermint extract and 2 to 3 drops of mint green gel food coloring, blending until consistent for that Shamrock Shake look.

5-Mix batter: Alternately add the dry ingredients and milk to the wet mixture, starting and ending with dry ingredients, and mix gently to keep the batter light.

6-Fill cupcake liners: Spoon the batter evenly into cupcake liners, filling each about two-thirds full, and prepare for baking at high altitudes.

7-Bake cupcakes: Bake for 18-20 minutes or until a toothpick comes out clean; times may vary, so check early to avoid overbaking.

8-Cool cupcakes: Allow cupcakes to cool in the pan for 5 minutes, then move to a wire rack to cool completely before adding frosting.

9-Prepare and pipe frosting: Prepare buttercream frosting, fill a large piping bag fitted with a star tip halfway, and pipe swirls onto cooled cupcakes.

10-Decorate cupcakes: Decorate with drained maraschino cherries, cereal marshmallows, and sprinkles, and optionally add striped paper straws for a fun touch.