Position rack in center of oven and preheat to 350. Lightly butter and flour 8 inch square glass baking dish. Stir flour, 1 cup sugar, brown sugar, lemon peel and cinnamon in a large bowl to blend. Add oil and lemon juice and mix until flour is evenly moistened and mixture forms clumps. Set aside 1 cup of mixture for topping. Whisk sour cream, egg, vanilla, baking powder and baking soda in small bowl until well blended. Using electric mixer, add sour cream mixture to crumb mixture and beat until batter is smooth. Spread batter in prepared pan. Sprinkle reserved crumb mixture over top. Bake about 40 minutes. Sift powdered sugar over top of cake