Step 1

Preheat the oven to 350 degrees F (175 degrees C). Line a baking sheet with aluminum foil.

Step 2

Melt butter in a microwave-safe bowl in a microwave. Add sugar and stir to combine. Add beaten egg and mix well. Stir in oats, flour, vanilla extract, salt, and baking powder.

Step 3

Drop teaspoonfuls of dough onto the prepared baking sheet.

Step 4

Bake in the preheated oven until edges are golden brown, about 8 minutes. Let cool completely before removing cookies from foil.