Preheat oven to 350°F. Coat 9×13” baking pan with nonstick cooking spray. Combine all ingredients for bottom layer in large bowl. Press into even layer in prepared baking pan.
Add cream cheese, butter, eggs, vanilla and the pinch of salt to large mixing bowl. Beat together with electric mixer until combined. Add powdered sugar, 1 cup at a time, beating until smooth. Pour mixture over crust mixture. Bake 40 minutes, until golden-brown and puffed. Center of pan should still jiggle when done.
Let cool and sprinkle with powdered sugar. Cut into squares and serve.