Preheat oven to 350°F. Line a metal 9x13” pan with foil and spray with cooking spray.
Cream brown sugar and butter in the bowl of an electric mixer fitted with a paddle attachment. It will be crumbly.
Add eggs and vanilla and beat until combined. Add cocoa, baking powder, salt, and flour and mix. Carefully mix in red food coloring and vinegar.
Stir in white chocolate chips.
Press into prepared pan (dough is sticky, spray your hands with cooking spray to avoid it sticking to your hands).
Bake or about 23-25 minutes, once they just lose their glossy sheen. (Be careful not to overcook - the center will still be jiggly when you take these out of the oven and they will finish cooking and firming up as they cool.) Cool completely before slicing into squares.
You must use a metal pan when baking these brownies. They will not bake properly in a glass or porcelain pan.