In a bowl, combine the flour, cocoa powder, baking soda and salt. Set aside.
In a large bowl, cream together the butter, brown sugar and white sugar. Beat in the egg and vanilla extract. Mix in the flour mixture and chocolate chips. Cover and refrigerate for 1 hour.
Using a cookie scoop, place a scoop of cookie dough in your hand and place a peppermint patty on top. Place another scoop of cookie dough on top and form together. Place stuffed cookies onto cookie sheets.
Bake for 14 minutes, or until done.
Recipe by Sugar, Spice and Family Life at https://sugarspiceandfamilylife.com/2016/12/peppermint-patty-stuffed-chocolate-cookies-recipe.html