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

In a large mixing bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy, about 2-3 minutes. Add the egg and vanilla extract, mixing until smooth.

In a separate bowl, whisk together the flour, baking powder, and salt. Gradually add this mixture to the wet ingredients, stirring gently until thick and slightly sticky.

Using a cookie scoop, portion out 7-8 dough balls on the baking sheet, flattening them to about 3/4 inch thick.

Bake for 12-13 minutes until edges are golden; cool on the sheet for 10 minutes before transferring to a wire rack.

For frosting, cream softened butter, then gradually add powdered sugar, vanilla extract, and cream until fluffy. Beat in butterscotch syrup for flavor.

Once cookies are cool, decorate with butterscotch frosting and sprinkle with Harry Potter-inspired sprinkles if desired.