Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a medium bowl, whisk together the flour, baking powder, and salt.

In a large mixing bowl, cream together the softened butter and packed brown sugar for 2-3 minutes until fluffy.

Add in the egg and vanilla extract, mixing until fully incorporated.

Gradually add the dry ingredients to the wet mixture, stirring gently until a soft dough forms.

Wrap the dough in plastic wrap and refrigerate for 15-20 minutes.

Roll out the chilled dough on a floured surface to about ¼ inch thickness.

Cut out shapes using cookie cutters and place them on the baking sheet.

Bake for 15-20 minutes or until the edges are golden brown. Cool on a wire rack.

Prepare the glaze by mixing powdered sugar with milk until smooth.

Drizzle the glaze over cooled cookies and add sprinkles if desired.

Let the glaze set, then serve and enjoy your cookies!