Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a mixing bowl, whisk together the flour, cocoa powder, baking powder, and salt. Set aside.
In another bowl, beat the softened butter, granulated sugar, and brown sugar together until light and fluffy.
Add in the vanilla extract and egg, mixing until well combined.
Gradually incorporate the dry ingredients into the wet mixture, stirring until a dough forms.
Use a cookie scoop or tablespoon to portion out the dough, rolling each ball into a 1-inch size.
Place the cookie balls on the prepared baking sheet, leaving some space between each.
Bake in the preheated oven for 10-12 minutes, until they are set but still soft.
Allow the cookies to cool on the baking sheet for about 5 minutes before rolling them in powdered sugar while they are still warm.
Let the cookies cool completely on a wire rack, then roll them in powdered sugar again for a snowy finish.
For added flavor, consider mixing in chocolate chips or experimenting with different extracts.
Store the cookies in an airtight container for up to one week.