Melt ½ cup of butter in a microwave-safe bowl until just melted, then let it cool.

In a large mixing bowl, combine cooled butter, granulated sugar, brown sugar, egg, and vanilla extract. Whisk until smooth.

Add 1 tablespoon of red gel food coloring and mix until the color is evenly distributed.

In a separate bowl, whisk together all-purpose flour, cocoa powder, baking powder, baking soda, and salt.

Gradually fold the dry ingredients into the wet mixture until just combined.

Let the dough rest at room temperature for 10 minutes while preheating the oven to 350°F.

Portion the dough into balls and roll in red sanding sugar, then place on a baking sheet.

Bake for 9-10 minutes until edges are set. Cookies should look soft in the center.

Let cookies cool on the baking sheet for 5-10 minutes before transferring to a wire rack.