01 - Whisk together flour, baking powder, and salt in a medium bowl. Set aside for later use.
02 - Beat softened butter and granulated sugar with electric mixer until light and fluffy, approximately 2-3 minutes.
03 - Add egg and vanilla extract to butter mixture, mixing until fully incorporated.
04 - Gradually add dry ingredients to wet mixture on low speed until smooth dough forms.
05 - Divide dough in half, flatten into discs, wrap in plastic, and refrigerate for minimum 1 hour.
06 - Preheat oven to 350°F and line two baking sheets with parchment paper.
07 - On floured surface, roll dough to 1/4-inch thickness. Cut heart shapes and transfer to prepared sheets.
08 - Bake for 8-10 minutes until edges begin turning golden. Cool 5 minutes on sheet before transferring to rack.
09 - Whisk powdered sugar, milk, and vanilla extract until smooth. Add food coloring if desired.
10 - Spread or drizzle glaze over completely cooled cookies. Add sprinkles and allow glaze to set before serving.