- 1 1/ 4 cup granulated sugar
- 1 cup (16 tablespoons or 2 sticks) unsalted butter, at room temperature
- 1 tablespoon vanilla extract
- 1/ 2 teaspoon baking powder
- 1/ 2 teaspoon salt
- 1 large egg, room temperature
- 3 cups all-purpose flour
- 1/ 2 teaspoon liquid red food coloring or 1/4 teaspoon if gel
- 1/ 4 teaspoon peppermint extract (optional if you want the red layer to taste minty)
In a bowl of an electric mixer fitted with the paddle attachment, cream the butter and sugar together on medium speed, until light and fluffy. Add in egg and vanilla and mix until combined.
In a separate medium bowl, whisk together flour, baking powder and salt.
With your mixer on low speed, gradually add the flour mixture into the butter-sugar mixture until the flour is incorporated, scraping down the bottom and sides of the bowl part way through.
Divide the dough in half, leaving one half in the mixer bowl and the other in a separate bowl (you could drop it back into the bowl you mixed the flour in). Add the red food coloring and peppermint extra (if using) to the dough in the mixing bowl and mix until color is evenly distributed.
Place each dough half on its own piece of waxed or parchment paper and then cover each with another sheet. Roll each portion of dough out into a 16 x 10-inch rectangle. Remove waxed paper from the top of each portion and then sandwich the red rectangle over the plain one (you can put the dough in the refrigerator between steps if it is getting sticky). Remove the other parchment from the top of the rectangle stack and then starting with a long side, roll the two doughs up. Wrap in plastic. Refrigerate until firm, 2-4 hours or overnight.
Preheat your oven to 350° F and line two cookie sheets with parchment paper. Unwrap and cut the chilled dough into 1/4-in. Slices and place on prepared cookie sheets with 2 inches between each. Bake until the edges get ever so slightly golden, about 12-14 minutes. Transfer to racks to cool completely.