Halloween Chocolate M&M Cookies

Preheat the oven to 350℉ (177℃). Prepare baking sheet pans with silicone baking mats or parchment paper sheets.
In the bowl of a stand mixer fitted with a paddle attachment or in a large bowl with an electric hand mixer, cream together the unsalted butter, light brown sugar, and granulated sugar until smooth and creamy. Add in the eggs and vanilla extract and mix until smooth.
Add in the all-purpose flour, dark cocoa powder, baking soda, and salt and mix on low speed until the cookie dough forms. Fold in the semisweet chocolate chips and Halloween M&M candies until well dispersed throughout the cookie dough.
Portion the cookie dough using a large cookie scoop (3 tablespoon). Place the cookie dough balls on the prepared baking sheet pans, allowing room for spreading. Press additional chocolate chips and M&Ms into the cookie dough.
Bake the cookies for 11 to 12 minutes until the edges are set. Allow the cookies to cool on the pan for 2 minutes and then transfer to a wire rack to cool completely.