In a medium bowl, whisk together flour, baking powder, and salt. Mixing them first helps distribute the leavening evenly so every cookie bakes consistently.
In a large bowl, beat the softened butter and sugar until light and creamy. Then add the egg and vanilla extract, mixing until smooth. Creaming properly is key to achieving that soft, delicate crumb.
Gradually mix the dry ingredients into the wet mixture. Don’t overmix — stop once the flour disappears. Overmixing can make the cookies tough. The dough should be soft but not sticky.
Divide the dough into two portions. Roll one out on a lightly floured surface to about ¼ inch thick. Use your favorite cookie cutters to make holiday shapes. Re-roll scraps to use all the dough.
Transfer cookies to a parchment-lined baking sheet and bake at 350°F for about 10 minutes, or until the edges just start turning golden. You’ll know they’re ready when they look set but still pale on top.
Let cookies rest on the baking sheet for a few minutes, then move them to a cooling rack. They need to be completely cool before decorating, or your icing will melt right off!