In a mixing bowl, whisk together 2 cups of all-purpose flour, 1/2 cup of unsweetened cocoa powder, 1 teaspoon of baking soda, and 1/2 teaspoon of salt. Set aside.

Use an electric mixer to beat 1/2 cup of softened butter with 1/2 cup of granulated sugar and 1/2 cup of brown sugar until light and fluffy, about 3-4 minutes. Add 2 eggs and 1 teaspoon of vanilla extract and mix until smooth.

Gradually add the dry ingredients to the wet mixture, mixing at low speed until just combined.

Measure out 2-ounce portions of cookie dough, roll into balls, and slightly flatten. Arrange on a baking sheet lined with parchment paper.

Press 3 to 4 M&M's into the top of each cookie dough disk.

Preheat your oven to 350°F (175°C). Bake cookies for 9-11 minutes, until set around the edges and soft in the center.

Allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.