Preheat the oven to 350 degrees. Prepare a 9x13 baking pan (metal recommended--not glass) by spraying with cooking spray and lining with parchment paper, letting the edges hang over each side.

Melt the butter, then pour it into a large mixing bowl. Stir in the brown sugar, then add the eggs and mix well.

Sift the dry ingredients and add to the sugar and butter mixture. Mix until combined, then stir in the butterscotch chips. The mixture will be a bit sticky.

Press into the 9x13 pan evenly, then bake for 20-25 minutes, or until golden brown. Let cool, then lift the brownies out of the pan and cut into pieces.