In a medium bowl, whisk together the cocoa powder, flour, baking soda, and salt. Set aside.
¾ cup Cocoa Powder, 2 cups Flour, 1 teaspoon Baking Soda, 1 teaspoon Salt
Using an electric mixer, cream the butter and brown sugar together until light and fluffy. Add in the eggs and mix until incorporated. Add in the vanilla extract, mixing to combine.
1 cup Unsalted Butter, 1½ cups Brown Sugar, 2 large Eggs, 1 teaspoon Pure Vanilla Extract
Add the flour mixture to the butter mixture and mix on low until combined. You don't want the flour going everywhere.
Cover the bowl and place it in the fridge until the dough is chilled, 30 minutes to 1 hour.
Preheat the oven to 350℉. Line baking sheets with silicone mats or parchment paper.
Put the nonpariels into a small bowl. Using a cookie scoop, roll the dough into a ball and then in the nonpareils, covering the ball completely. Place onto the prepared baking sheet about 2 inches apart.
Bake for 9 to 11 minutes until the edges are set. Remove from the oven and cool cookies for 5 minutes before removing to a wire rack to cool completely before storing.