Cut your cold butter into tablespoon-sized cubes for easier mixing. In a stand mixer, beat the butter and brown sugar on high speed for 2-3 minutes until the mixture is light and fluffy. This step is crucial for aerating the dough, which gives you thick, bakery-style cookies.

Crack in one egg at a time, beating for about a minute after each addition. This ensures the eggs are fully incorporated and gives the dough a silky texture. Don’t rush it—good things take time!

In a separate bowl, whisk together the flour, cocoa powder, cornstarch, baking soda, and salt. Make sure everything is evenly combined—nobody wants a mouthful of baking soda!

Gradually fold the dry ingredients into the wet mixture. The dough will be thick, so don’t be afraid to put a little muscle into it. This is your arm workout for the day.

Fold in the chocolate chips and chopped peppermint bark. Take a moment to marvel at how festive your dough looks.

Cover the dough and pop it in the fridge for at least 30 minutes (up to 24 hours). Chilling the dough makes the cookies thicker and more flavorful.

Preheat your oven to 415°F (213°C). Scoop the dough into 12 large balls (about 1/3 cup each) and place them on a baking sheet lined with parchment paper. Bake for 10-12 minutes until the edges are set, but the centers still look slightly underbaked.

Let the peppermint chip cookies rest on the baking tray for 10 minutes before transferring them to a wire rack. This step allows them to firm up while staying soft and gooey inside.