This recipe uses US measurements.
1 cup flour
1/4 cup powdered sugar
1/2 cup butter
3 tablespoons fresh lemon juice
3/4 cup granulated sugar
1/2 tablespoon or to taste lemon zest
2 tablespoons flour
1/4 teaspoon baking powder
Stir A together until crumbly. Press into the bottom of and 8 inch X 8 inch baking pan. Bake at 350 F for 10 minutes or until slightly browned. Cool.
Beat B together at high speed of mixer for 10 minutes. Add C and blend only until it is moistened. Pour this mixture over the crust and bake at 350 F for 20-25 minutes.
Cool. Cut into bars.