Preparation

• Preheat the oven to 350°F (175°C). Line a baking sheet with parchment paper.
• In a large bowl, beat the softened butter and sugar until light and fluffy, about 2–3 minutes.
• Add the egg and vanilla. Mix until fully combined.
• In a separate bowl, whisk together the flour, baking powder, and salt.
• Gradually add the dry ingredients to the wet mixture. Mix until a soft dough forms. Do not overmix.
• Divide the dough into two equal portions. Add a few drops of pink food coloring to one portion and knead until uniformly colored.
• On parchment paper, roll each portion into a thin rectangle (about 1/8–1/4 inch thick).
• Carefully place one rectangle on top of the other and press gently to adhere. Starting from a short end, roll the layered dough tightly into a log. Seal the seam by pinching the edge.
• For cleaner slices, wrap the log in plastic and chill for 20–30 minutes. (You can bake immediately if you prefer looser swirls.)
• Slice the log into rounds about 1/4–1/2 inch thick and place them on the prepared baking sheet, spaced about 1 inch apart.
• Bake for 10–12 minutes, until the edges are just starting to turn light golden.
• Remove from the oven and immediately add sprinkles while the cookies are still warm so they stick. Transfer to a wire rack to cool completely.