Step 1: Prepare the Dough

1. Preheat the Oven: Preheat your oven to 350°F (175°C) and line baking sheets with parchment paper.
2. Cream Butter and Sugars: In a large mixing bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy.
3. Add Eggs and Vanilla: Beat in the eggs one at a time, followed by the vanilla extract, mixing well after each addition.

Step 2: Combine Dry Ingredients

1. Mix Dry Ingredients: In a separate bowl, whisk together the all-purpose flour, cocoa powder, baking soda, and salt.
2. Combine Mixtures: Gradually add the dry mixture to the wet mixture, mixing until just combined.

Step 3: Add Chocolate and Peppermint

1. Fold in Chocolate Chips: Stir in the semi-sweet chocolate chips and crushed peppermint candies until evenly distributed throughout the dough.

Step 4: Chill the Dough (Optional)

• For thicker cookies, chill the dough in the refrigerator for about 30 minutes before baking. This helps the cookies maintain their shape.

Step 5: Bake the Cookies

1. Scoop the Dough: Using a cookie scoop or tablespoon, drop rounded balls of dough onto the prepared baking sheets, spacing them about 2 inches apart.
2. Bake: Bake in the preheated oven for 10-12 minutes, or until the edges are set but the centers are still soft. They will continue to cook slightly as they cool.

Step 6: Cool and Garnish

1. Cool the Cookies: Allow the cookies to cool on the baking sheets for about 5 minutes before transferring them to wire racks to cool completely.
2. Garnish: If desired, sprinkle additional crushed peppermint candies and chocolate chips on top of the warm cookies for an extra festive touch.