Preheat oven to 350F. Line two large baking sheets with parchment paper.
Add flour, cocoa, baking soda and salt to a medium size bowl. Whisk to combine.
In a large bowl, add melted butter, brown sugar and granulated sugar. Beat with electric mixture on medium speed for one minute.
Add eggs and vanilla. Beat with electric mixture on medium speed for one minute or until the batter is smooth. Use a spatula to scrape down the sides of the bowl.
Add half of the flour mixture to the batter. Turn electric mixer to low and mix until the flour mixture starts to incorporate into the batter. As the flour mixture starts to incorporate, you can increase the speed of the electric mixer to medium. Use a spatula to scrape down the sides of the bowl as necessary. Repeat with remaining flour mixture.
Add mint chocolate chips.
Use a spatula to fold in the mint chocolate chips.
Using a spoon or your hands, shape approximately 2 tablespoons of dough into a ball. Place dough ball onto baking pan. Repeat until the baking sheets are full. Leave 1.5 to 2 inches between cookies so they have room to spread as they bake.
Place baking pan into preheated oven and bake for 10-12 minutes. The cookies are ready when small cracks start to form on the tops. Remove pan from oven. Let cookies cool slightly before transferring to a wire rack to cool completely. Repeat with other baking sheet. Makes 24 cookies.
Enjoy!