Freeze 12 peppermint kisses for at least 2 hours on a tray.

Cream together 0.5 cup unsalted butter, 0.5 cup sugar, and 0.5 cup light brown sugar for 2-3 minutes.

Incorporate 2 egg yolks and 1 teaspoon vanilla extract until smooth.

In a separate bowl, whisk together 1.5 cups all-purpose flour, 0.5 cup cocoa, 0.5 teaspoon sea salt, 0.5 teaspoon baking powder, and 0.25 teaspoon baking soda.

Gradually add dry ingredients to wet ingredients, mixing on low until just combined.

Cover dough and refrigerate for 3 hours.

Preheat oven to 350°F (175°C). Roll the dough into 1-inch balls and bake for 7-8 minutes.

Press a frozen peppermint kiss into the center of each warm cookie.

Cool cookies on a wire rack completely.