Preheat the oven to 350 degrees. Spray a baking sheet with cooking spray.
Combine flour, corn meal, baking powder and salt in a bowl.
With and electric mixer on high speed, beat the granulated sugar, egg, water, oil, lemon zest and lemon extract until blended. on low speed add the flour mixture, beating just until combined.
Place the dough in 2 (12) inch logs, 3 inches apart. Bake until golden about 20 minutes. Cool for 10 minutes on sheet. Cut across the log into 1/2 in slices. Arrange slices slightly apart and bake an additional 15 minutes. Cool completely on wire rack.
Mix powdered sugar and lemon juice together and drizzle over cooled biscotti. Let set for about 2 hours for icing to set.
