Preheat oven to 350 degrees.

In a microwave safe bowl melt the butter and transfer into a mixing bowl. Add the brown sugar and whisk to combine. Add the vanilla and egg and continue to whisk until totally incorporated.

In another bowl mix together the dry ingredients, flour, baking powder, salt, and baking soda.

Slowly add the dry ingredients to the wet ingredients until fully combined. The batter will be a bit stiff but not to worry!

In the same 8x8 metal pan, carefully layer the blondie brownie mixture over the brownie mixture. Bake for 20-22 minutes in a 350 degree oven or until you stick a knife in and it comes out clean.