Whisk the dry ingredients (flour, baking powder, and salt) together in a large bowl and set aside.

In a stand mixer fitted with the paddle attachment, beat the softened butter and superfine sugar on medium speed until pale and fluffy, about 2–3 minutes.

Add the egg and almond extract, mixing just until combined and scrape down the bowl.

Reduce speed and add the dry ingredients, mixing until a cohesive dough forms; avoid overworking.

Divide the dough evenly into two portions. Color one portion red with gel coloring, kneading lightly until uniform.

Roll each portion between sheets of parchment to 1/4-inch thickness and chill for 1 hour to firm up.

Remove sheets from fridge. Place the red sheet on top of the plain sheet, trim edges to create a neat rectangle.

Moisten the seam lightly with water to help layers stick together.

Starting from one long edge, roll the dough tightly into a log, pressing gently to eliminate air pockets.

Wrap the log tightly in plastic wrap, then in parchment. Chill for at least 2 hours or overnight.

Preheat the oven to 350°F (180°C) and line baking sheets with parchment.

Let the chilled log sit at room temperature for 5–10 minutes for easier slicing.

Using a sharp, un-serrated knife, cut 1/4-inch-thick cookies and space them about 2 inches apart on prepared trays.

Bake cookies for 11–12 minutes, until edges are set but centers remain pale.

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