Set up area with ingredients and preheat oven to 325.
Set up cupcake pans with nonstick spray or paper cupcake holders.
In a large bowl, beat sugar and butter until thick and creamy.
Add eggs one at a time, mixing well after each addition.
Gradually add milk, followed by vanilla extract.
In a separate bowl, whisk together flour, baking powder, salt, and cocoa powder.
Slowly add dry ingredients to wet ingredients, blending until just combined.
Mash up thin mint cookies (or desired mint candy substitute) until you have half a cup.
Add mashed cookies and dark chocolate chips to batter.
Add additional mint extract if desired.
Fill cupcake tins halfway to three-quarters full.
Bake for 12-14 minutes, keeping a close eye on them.
Let cupcakes cool in tins for at least 10 minutes before transferring to a wire rack.
Ice cupcakes as desired and enjoy!