Christmastime is synonymous with thumbprint cookies, most often prepared with chocolates or preserves. So, let's shake it up a bit by pressing chocolate mint patties into the cookie dough. These are the perfect holiday confection for the mint lover in your life!
Start by placing the softened butter and sugar into a mixing bowl. Use a hand-held mixer to beat the butter and sugar together until it forms a light and fluffy mixture. This should take about three minutes.
Now, add the egg yolk, milk, and extract. Beat until well combined with the butter and sugar mixture.
Next, in another bowl, sift together the flour, cocoa powder, and salt. Remember, if you used salted butter, do not add the additional salt here! Add this to the butter mixture and beat until just combined.
Cover and refrigerate for one hour.
In the meantime, pour the sprinkles into a bowl big enough to roll the cookie balls into. Secondly, line a baking sheet with parchment paper and set aside.
Preheat oven to 350 degrees F.
Using one tablespoon of dough at a time, roll the dough into balls and then into the sprinkles. Place on the prepared baking sheet and use a measuring teaspoon to push an indent into the center of the ball. You can use your thumb too if you wish.
Place each ball two inches apart. Bake for 11 minutes.
While the cookies bake, unwrap the peppermint patties so that they are ready to go. Once baked, remove from the oven and immediately press an unwrapped patty into the thumbprint you made earlier. Press down gently, but firmly so that the patty sticks to the cookie.
Transfer cookies to a cooling rack to cool completely.