Preheat the oven to 350F. Spray an 8x8" baking pan with non-stick cooking spray or line with parchment paper and set it aside.
In a small bowl, whisk together the flour, baking powder and salt. Set it aside.
Whisk together the butter and brown sugar until combined and no lumps remain. Then whisk in the egg and vanilla.
Use a rubber spatula to combine the dry ingredients into the wet until just combined. Then fold in the butterscotch chips (or whatever you're using. Pictured are made with sea salt caramel chips).
Pour the batter into the prepared baking pan and bake for 18-24 minutes, or until a toothpick comes out mostly clean but with a few moist crumbs.
Allow them to cool completely before cutting into squares. Store them covered at room temperature.
