In a bowl, combine flour, salt and 1/3 cup sugar. Cut in butter until the mixture resembles fine crumbs; press into the bottom of a greased 13x9x2-inch baking pan. Arrange the apple slices on top of crumbs;
sprinkle with lemon juice. Combine 1/3 cup sugar with cinnamon; sprinkle over apples. Bake at 375 deg. for 20 min. Meanwhile, in a small bowl, combine remaining sugar with the rest of the ingredients. Spoon over baked apples; bake for another 20 minutes or until golden brown. Cut into squares while still warm,