In a large bowl, cream together the softened butter and granulated sugar until light and fluffy.

Beat in the egg, vanilla extract, and peppermint extract until well combined.

Whisk together the flour, baking powder, and salt in a separate bowl.

Gradually add the dry ingredients to the wet ingredients, mixing until a stiff dough forms.

Divide the dough into two equal portions.

Add the red gel food coloring to one portion and knead until the color is uniform.

Wrap each dough ball in plastic wrap and refrigerate for at least 1 hour.

Roll out the vanilla dough on a piece of parchment paper into a 12x9 inch rectangle.

Roll out the red dough on a separate piece of parchment paper into a 12x9 inch rectangle.

Carefully flip the red dough onto the vanilla dough and remove the top layer of parchment.

Roll the stacked dough tightly into a log starting from the long edge.

Roll the log in festive nonpareil sprinkles to coat the outside.

Wrap the log in plastic and refrigerate for at least 1 more hour until firm.

Preheat oven to 350°F (175°C) and line baking sheets with parchment paper.

Slice the log into 1/4-inch thick rounds and place on baking sheets 2 inches apart.

Bake for 8 to 10 minutes until the edges are just set but not browned.

Cool on the baking sheet for 5 minutes before transferring to a wire rack.