Add 1 cup chocolate chips and 2 tablespoons of butter to a glass bowl.
Microwave in 20 second increments until melted. It will probably take 3 times to melt thoroughly. Stir until creamy.
Add espresso powder to chocolate mixture and stir until combined. Set aside.
Place the rest of the stick of butter in a large bowl. Mix on medium high using an electric hand mixer until creamy.
Add granulated sugar and brown sugar to butter and mix continue to mix.
Blend in egg, vanilla, and peppermint extract.
Add in the chocolate mixture and blend well. Set aside.
Mix together flour, baking powder, and salt.
Using a wooden spoon, slowly stir flour mixture into wet ingredients.
Cover bowl with plastic wrap and place in refrigerator for at least 2 hours. Overnight is best as these cookies tend to spread.
Preheat oven to 350º
Line baking sheet with parchment paper or a baking mat.
Scoop 1 tablespoon of dough per cookie and place on cookie sheet. Leave 2 inches between cookies.
Bake at 350º degrees for 10 minutes. As oven temperatures vary, check at 8 minutes. The cookies will still be a little soft in the middle when done.
Allow cookies to cool on cookie sheet for 5 minutes.
Move cookies to wire rack to cool completely