01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - Whisk together flour, baking powder, baking soda, and salt in a medium bowl until evenly distributed.
03 - Beat softened butter and granulated sugar in a large bowl until light and fluffy, approximately 2–3 minutes.
04 - Incorporate eggs one at a time, then mix in milk and vanilla extract until fully combined.
05 - Gradually add dry ingredients to wet mixture, mixing just until flour streaks disappear. Avoid overmixing.
06 - Drop rounded tablespoons of dough onto prepared baking sheets, leaving 2 inches of space between each cookie.
07 - Gently flatten dough tops and press sprinkles or colored sugar into surface if desired.
08 - Bake for 9–11 minutes until edges are set but centers remain soft. Do not overbake.
09 - Let cookies rest on baking sheet for 5 minutes, then transfer to wire rack to cool completely.
10 - Pipe or spread icing over cooled cookies and add additional sprinkles as desired.