Preheat oven to 350°F (175°C).
Cream butter and sugars together in a large bowl.
Add vanilla and peppermint extract, mixing well.
In a separate bowl, whisk flour, cocoa powder, baking soda, and salt.
Gradually add the dry ingredients to the butter mixture.
Stir in chocolate chips.
Scoop dough onto a baking sheet and bake for 10-12 minutes.
For iced coffee: brew coffee, let it cool.
Fill a glass with ice and pour in the cooled coffee.
Add milk, sugar, and peppermint extract, then stir.
Serve the iced coffee with freshly baked cookies.