To make crust: Mix together the butter, 1 1/3 cups flour and 1/4 cup sugar with a fork until crumbly. Press into an 8 inch square pan and bake for 20 minutes. Crust will look white. Do not brown!
Combine the eggs, 3/4 cup of sugar, 2 tablespoons flour, baking powder and lemon juice in a blender. Blend until well mixed. Pour over pre-baked crust.
Return to oven and bake an additional 20 minutes. Remove from oven and sprinkle with powdered sugar. Let bars cool before cutting.
