Preheat the oven to 350° F. Lightly grease a 9X9 pan with cooking spray. In a large bowl using a hand mixer, beat butter and both sugars until light and fluffy.
Add eggs and vanilla to the sugar mixture. Mix until combined!
In another bowl, whisk together flour, cinnamon, baking powder, and salt. Add dry ingredients to wet ingredients and beat until just combined.
Press batter into the prepared pan and sprinkle top with cinnamon sugar.
Bake until golden and still slightly soft in the middle, 25-30 minutes.
Let cool and slice into squares.
Notes
This recipe is easily doubled! Just bake in a 9X13.