Preheat your oven to 350°F (175°C) and spray mini muffin pans with baking spray.

In a large mixing bowl, beat the softened butter until creamy, then add powdered sugar, baking powder, and salt, mixing until smooth.

Blend in the egg and vanilla extract, beating until fully incorporated.

Slowly add the flour, mixing on low speed until just combined.

Divide the dough into two bowls, mixing green sprinkles into one half and red into the other.

Shape the dough into 1-inch balls and place in muffin tins, pressing down to create cup shapes.

Bake for 8-10 minutes until edges are lightly golden brown.

Cool in pans for 5 minutes before transferring to a wire rack.

Beat together softened butter, powdered sugar, vanilla extract, and salt for the frosting. Add milk to reach spreadable consistency.

Frost each cookie cup with the prepared frosting and sprinkle with additional festive sprinkles.