1-First, whisk the flour, cocoa powder, baking powder, and salt in a medium bowl, then set it aside. This step ensures even distribution of flavors.

2-Next, use an electric mixer to beat the butter and sugar on high speed for 2 minutes until smooth and creamy, then add the egg and vanilla, beating for another minute while scraping the bowl as needed.

3-Combine the dry ingredients with the wet ones on low speed until everything mixes together. If the dough feels sticky, add an extra tablespoon of flour. Divide the dough in half and roll each part to 1/4-inch thickness on parchment paper dusted with cocoa powder or flour. To keep things simple, chill the dough by lightly dusting one layer, covering it, stacking the second, and wrapping in plastic for 1 to 2 hours.

4-Once chilled, preheat your oven to 350°F (177°C) and line baking sheets with parchment. Cut shapes from the dough and re-roll scraps quickly, chilling if it softens. Arrange the cookies 3 inches apart and bake for 11-12 minutes until the edges set, rotating trays halfway through. Let them cool on the sheets for 5 minutes, then move to wire racks.

5-After cooling, decorate with royal icing or easy glaze icing, adding sprinkles if you like, and let it set.