Step 1: In a large bowl, cream together the softened butter and granulated sugar with an electric mixer on medium speed until light and fluffy, about 2-3 minutes.
Step 2: Beat in the eggs one at a time, then stir in the vanilla extract until fully incorporated. Scrape down the sides of the bowl as needed.
Step 3: In a separate medium bowl, whisk together the all-purpose flour, baking powder, and salt.
Step 4: Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined and a soft dough forms. Be careful not to overmix.
Step 5: Divide the dough in half, flatten each half into a disk, wrap tightly in plastic wrap, and refrigerate for at least 1 hour, or up to 2 days, until firm.
Step 6: Preheat oven to 375°F (190°C). Line several baking sheets with parchment paper or silicone baking mats.
Step 7: On a lightly floured surface, roll out one disk of chilled dough to about 1/4-inch thickness. If the dough is too stiff, let it sit at room temperature for a few minutes.
Step 8: Use your favorite Christmas cookie cutters to cut out shapes. Carefully transfer the cut-out cookies to the prepared baking sheets, leaving about 1 inch between them.
Step 9: Bake for 8-10 minutes, or until the edges are lightly golden and the centers are just set. Baking time may vary depending on the size of the cookies. Do not overbake to keep them soft.
Step 10: Let the cookies cool on the baking sheets for 2-3 minutes before transferring them to a wire rack to cool completely.
Step 11: Once completely cooled, decorate the Christmas cookies recipes with royal icing, buttercream, sprinkles, or edible glitter as desired. Let the decorations set before storing.