In large mixing bowl, combine 2 cups flour, ¾ cup sugar and butter. Beat at medium speed until mixture resembles fine crumbs. Press mixture into a greased 13x9-inch baking pan. Bake in a preheated 350°F oven 20-22 minutes or until edges are lightly browned.
Meanwhile, in medium mixing bowl, combine remaining sugar, eggs, lemon juice, lemon zest and salt. Beat at medium speed until well mixed. Add remaining flour and baking powder; beat at low until just combined.
Spread blueberry filling over hot crust; carefully pour lemon filling over blueberries. Return to oven and continue baking 22-27 minutes or until filling is set and top is golden brown. Sprinkle with powdered sugar while still warm.
Copyright © 2011 Supervalu, Inc. All Rights Reserved.