1-Getting started: Getting started with these Christmas sprinkle cookies is straightforward and fun, beginning with preheating your oven to 350°F (177°C) and lining two baking sheets with parchment paper for even baking. This step ensures your cookies come out perfectly without sticking, setting the stage for a smooth process. Cream the unsalted butter and 1 ½ cups granulated sugar together for 2-3 minutes until light and fluffy, creating a solid base for the dough.

2-Next, beat in the large egg, large egg yolk, 1 tablespoon whole milk, and 2 teaspoons vanilla extract until everything is smooth, scraping the bowl as needed to mix evenly. In a separate bowl, whisk together the 2 ¾ cups all-purpose flour (spooned and leveled), 1 ½ teaspoons baking powder, 3/4 teaspoon salt, and 1/2 teaspoon baking soda. Gradually add this dry mixture to the wet ingredients, mixing on low until a soft dough forms, then fold in the 1/2 cup red and green jimmies sprinkles to distribute the festive colors.

3-Scoop 1 ½ to 2 tablespoons of dough per cookie, roll into balls, and coat each in about 1/4 cup granulated sugar for a sparkling finish. At this point, you can chill the dough for 1 hour up to 3 days to prevent spreading, but bring it back to room temperature before baking. Bake for 8-10 minutes until the edges are set and the centers remain slightly soft, then cool on the baking sheet for 3-5 minutes before moving to a wire rack.