You'll need about 7 graham cracker sheets to get 1 cup of crumbs.
Preheat oven to 350°.
Weigh or lightly spoon flour into a dry measuring cup; level with a knife. Combine flour and next 5 ingredients in a large bowl; stir with a whisk. Combine oil, vanilla, and egg whites in a small bowl, stirring with a whisk; add to flour mixture, stirring just until moist. Lightly coat hands with cooking spray. Press batter into an 8–inch square metal baking pan coated with cooking spray.
Bake at 350° for 18 minutes or until a wooden pick inserted in center comes out clean. Cool in pan on a wire rack. Sift powdered sugar over top. Cut into bars.
Young Chefs can:
Crush graham crackers in a sealed plastic bag
Measure butterscotch morsels
Older Chefs can:
Stir together dry ingredients
Press batter into baking pan
