01 - In a medium bowl, whisk together the all-purpose flour, baking powder, and salt. Set aside.
02 - Using an electric mixer, beat the softened butter and granulated sugar until light and fluffy, approximately 2 minutes.
03 - Add the large egg, pure vanilla extract, and peppermint extract to the butter mixture and beat until fully combined.
04 - Gradually add the dry ingredients to the wet ingredients, mixing until a soft dough forms.
05 - Divide the dough in half. Add several drops of red gel food coloring to one half and mix until color is uniform.
06 - Roll each half between two sheets of parchment paper into approximately 9 by 7 inches rectangles, about 1/4 inch thick.
07 - Place the red dough rectangle carefully atop the plain dough rectangle, then remove the top parchment sheet.
08 - Starting from the long edge, roll the dough tightly into a log using the parchment paper to assist. Wrap tightly.
09 - Refrigerate the wrapped dough log for at least 1 hour until firm.
10 - Preheat oven to 350°F (175°C) and line baking sheets with parchment paper.
11 - Slice the chilled dough log into 1/4 inch thick rounds and arrange 2 inches apart on the prepared sheets.
12 - If desired, sprinkle crushed peppermint candies atop each cookie.
13 - Bake for 9 to 11 minutes until set but not browned. Cool on the baking sheets for 5 minutes, then transfer to a wire rack to cool completely.