Family Tested & Approved
Preheat oven to 350 degrees. Grease a 13 X 9 Pan with butter and set aside.
In a large microwave-safe bowl melt butter on high for 30 seconds.
Mix in the brown sugar until completely mixed. Add the baking powder, salt and vanilla. Gradually add the flour and mix well (the batter will be stiff).
Whisk the eggs in a small bowl and add to the batter, mixing well.
Spread the batter in the prepared pan and bake for approx. 30 min (do not over bake). Let cool completely before cutting into squares.