Preheat oven to 375 F. degrees. Grease a mini muffin pan.
Use an electric mixer to cream brown sugar, sugar, & butter.
Add egg & vanilla, mix.
In a separate bowl mix flour, baking powder, baking soda, & salt together. Add to the creamed butter/sugar. Beat with mixer until everything is mixed in. .
Scoop by the tablespoon (about 1" balls) and place in greased mini muffin pan.
Bake 9-10 minutes until the edges are just starting to brown
Recipe by THE SEMISWEET SISTERS at https://www.thesemisweetsisters.com/2018/08/18/mini-sugar-cookie-cups/