Heat oven to 350*. Grease 9" square baking pan. If desired line with foil. Combine 1 cup flour and 1/4 cup powdered sugar in small bowl. With pastry blender cut in butter until mixture resembles coarse crumbs. Stir in 1/2 cup pecans. Press evenly into bottom of pan. Bake 15 min or until light golden brown; cool completely on wire rack.

Whisk eggs in medium bowl until combined. Whisk in all remaining filling ingredients except pecans. Pour over cooled crust; sprinkle with 1 cup pecans. Bake 25 to 30 min or until puffed and golden brown. Cool in pan on wire rack.

Meanwhile, combine 1 cup powdered sugar, 1/2 tsp vanilla and 1 tbsp water in small bowl. If glaze is too thick, add additional water. Drizzle over bars.