In a large bowl (or bowl of a stand mixer), beat together butter, granulated sugar, and brown sugar until creamed (a uniform, light, and fluffy mixture).
Add in eggs and vanilla and stir until incorporated.
Slowly add in dry ingredients (baking soda, cocoa powder, and flour) and stir until a uniform dough has been created.
Cover and chill for at least 30 minutes.*
Place additional granulated (or mix of red decorating and granulated sugar) into a bowl.
Scoop 1 tablespoon sized portions of dough into your hand and roll into a ball. Roll each dough ball in the sugar and place 2-inches apart on a baking sheet.*
Bake at 350°F for 8-10 minutes.
Immediately after removing from the oven, gently push a peppermint kiss cookie into the center of each cookie.
Let cookies cool on the baking sheet for a few minutes, then move to a cooling rack to cool completely.
Store cookies in an air-tight container.