Combine the butter, 1 cup sugar, powdered sugar, vanilla, peppermint extract, and egg in a large bowl using the mixer’s low setting, then stir in the flour, baking powder, and salt. Stop once the dough comes together and no dry flour remains, keeping the mixing brief to protect its tenderness.

Separate the dough into equal halves, work red gel coloring into one half to reach your preferred shade, and wrap the two portions individually in plastic wrap before refrigerating for 3 to 4 hours. Both portions should feel firm rather than soft and greasy when you begin shaping.

Mix the finely crushed peppermint candies with the remaining 2 tablespoons granulated sugar in a small bowl and reserve it for topping. The candy pieces should distribute throughout the sugar so each sprinkle contains both.

Set the oven to 350°F and let it preheat before baking. A fully heated oven helps the chilled shapes begin setting promptly.

Portion 1 level teaspoon from each dough color, roll each piece into a 5-inch rope, and wind the two ropes around each other while pressing their ends together. Keep the ropes similar in thickness and secure their tips so the stripes stay joined rather than springing apart.

Arrange the paired ropes on an ungreased baking sheet with their tops curved into hooks, bake for 8 to 10 minutes, sprinkle immediately with the peppermint sugar, and transfer to a wire rack to finish cooling. Look for lightly browned bottoms and pale tops, and apply the topping while the cookies are hot so it can cling to the surface.