Apple Streusel Bars

4 large apples, peeled, cored, thinly sliced 
1 tablespoon lemon juice
1/2 cup cane sugar
2 tablespoons all-purpose flour
1 teaspoon cinnamon
2 cups all-purpose flour
1/2 cup cane sugar
1/2 teaspoon baking powder
2 sticks (1 cup) cold salted butter, cubed
1 egg, beaten

1. Preheat oven to 350°F. Spray a 9 x 13 inch baking pan with cooking spray.
2. In a large bowl, toss the apples with the lemon juice. Combine the flour, sugar, and cinnamon in a small bowl and sprinkle over the apples. Toss the apples until well coated. Set aside.
3. In medium bowl stir together 2 cups flour, 1/2 cup sugar, and baking powder. Or mix in the bowl of a food processor.
4. Cut in butter with a pastry cutter, until crumbly and thoroughly combined. (Or pulse the butter if using a food processor.)
5. Stir in the beaten egg and mix until dough pulls together. (Or pulse until dough pulls together.)
6. Press about 2/3 of the dough evenly into the prepared pan. Spread the apple slices over the crust. 
7. Crumble the remaining dough over the apples. Bake 45 minutes until golden brown.
8. Let cool before cutting. Serve with vanilla ice cream or whipped cream.