📖 Instructions

1. Prepare the Dough: In a large mixing bowl, cream together the unsalted butter and granulated sugar until the mixture is light and fluffy. Use a stand mixer with a paddle attachment or a hand mixer for best results. This usually takes about 2-3 minutes.
2. Add Wet Ingredients: Beat in the egg and vanilla extract until well combined, scraping down the sides of the bowl as needed to ensure everything is incorporated evenly. Continue mixing for another minute until smooth.
3. Combine Dry Ingredients: In a separate medium bowl, whisk together the all-purpose flour, baking powder, and salt. Make sure there are no lumps in the flour mixture.
4. Gradually Add Dry to Wet: Slowly add the dry ingredients to the wet ingredients, mixing on low speed until just combined. Be careful not to overmix the dough, as this can make the cookies tough. The dough might seem a bit crumbly at first, but it will come together.
5. Chill the Dough: Divide the dough in half and flatten each half into a disc. Wrap each disc tightly in plastic wrap. Refrigerate for at least 1 hour, or up to 2 days. Chilling is crucial; it prevents the cookies from spreading too much during baking and makes them easier to handle.
6. Preheat Oven and Prepare Baking Sheets: When ready to bake, preheat your oven to 375°F (190°C). Line two large baking sheets with parchment paper or silicone baking mats. This prevents sticking and ensures even baking.
7. Roll Out the Dough: On a lightly floured surface, unwrap one disc of chilled dough. Roll it out to about 1/4 inch thickness. If the dough is too cold and hard to roll, let it sit at room temperature for 5-10 minutes.
8. Cut Out Shapes: Using your favorite Christmas cookie cutters, cut out shapes from the rolled dough. Try to cut them as close together as possible to minimize scraps. Carefully transfer the cutouts to the prepared baking sheets, leaving about 1 inch between each cookie. Re-roll any dough scraps once, combining them gently before cutting more shapes. Don't re-roll too many times, or the dough can become tough.
9. Add Sparkle: Lightly brush the tops of the cutout cookies with a tiny bit of milk or an egg wash (1 egg yolk whisked with 1 tsp water) if you want the sugar to really adhere, then generously sprinkle with coarse sparkling sugar. This is where the magic happens!
10. Bake the Cookies: Bake one sheet at a time in the preheated oven for 8-10 minutes, or until the edges are lightly golden. The baking time can vary depending on the size and thickness of your cookies, so keep an eye on them! They should be firm to the touch but still pale in the center.
11. Cool and Store: Let the cookies cool on the baking sheets for 5 minutes before transferring them to a wire rack to cool completely. Once fully cooled, store them in an airtight container at room temperature for up to 1 week. If you're stacking them, you might want to place a piece of parchment paper between layers to protect the sparkling sugar.
12. Optional Decoration: For extra flair, once completely cooled, you can pipe on some simple royal icing or drizzle with melted white chocolate and add more sprinkles. But honestly, they are perfect just with the sparkle!