Preheat oven to 325 degrees F. Spray bottom and sides of 9" x 13" pan with cooking spray.
Mix together in a large bowl with pastery cutter or back of fork until it forms a thoroughly combined crumbly texture. Press mixture into 9"
x 13" pan. Bake at 325 degree F for 20-25 minutes. When crust comes out of the oven, preheat oven to 350 degrees F.
In a blender, mix all batter ingredients on high until thoroughly combined. Pour batter into 9" x 13" pan over crust after it comes out of the oven. Bake at 350 degrees F for 25 minutes. Once you remove it from the oven, let it cool 5 minutes then dust the top with powdered sugar. Allow to completely cool, then cut into bars and serve. Enjoy!