In a small bowl, whisk together the flour, baking soda, baking powder, and salt. Set aside.

In a large bowl, whisk the melted butter with the brown and white sugars until smooth. Add the egg and vanilla extract, whisking for about 1 minute until well combined.

Gradually add the dry ingredients to the wet ingredients, mixing gently with a wooden spoon until a soft dough forms. Fold in the sprinkles for a festive touch.

Preheat your oven to 350°F (175°C). Roll the cookie dough into small balls, approximately 1 tablespoon each, and place them on a baking sheet lined with parchment paper, spacing them about 2 inches apart.

Bake the cookies for 10 minutes, or until the edges are lightly golden. Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.

Pair these cheerful Christmas cookies with a cold glass of milk, and enjoy the holiday spirit!