Add flour, unsweetened cocoa powder, baking soda, and salt in a large bowl.

Whisk to blend.

Set aside.

In a second large bowl, add the butter, both sugars.

With an electric mixer cream the butter and both sugars together until smooth.

Add in the egg and vanilla, beating until combined.

If needed, scrape down the sides of the bowl.

With the mixer still beating slowly, add in the dry ingredients.

Beat until all ingredients are just combined.

Cover the bowl of cookie dough with plastic wrap.

Place in the refrigerator for 30 minutes or so.

Preheat the oven to 350 degrees.

Line two cookie sheets with parchment paper. Set aside.

Scoop out the cookie dough with cookie scoop #40 (or two tablespoons).

Place the cookie dough balls onto the cookie sheets, several inches apart.

Use the bottom of a glass and flatten each cookie dough ball.

Place a mini peppermint patty in the center of the cookie dough.

Pull the dough around the peppermint patty.

Work to make sure that the cookie dough is folded around the patty and closed completely.

Bake at 350 degrees for 10-12 minutes.

Allow cooling slightly while still on the cookie sheet.

Transfer each cookie to a cooling rack.