1. Preheat oven to 350 degrees F.
2. Cream sugar and butter in a mixer for 2 minutes.
3. Add milk, ricotta, vanilla, egg, and lemon juice and zest. Mix on medium speed 1 to 2 minutes or until well combined.
4. In a small bowl, combine flour, cornmeal, baking powder, and salt. Mix well.
5. Add flour mixture to milk mixture and fold gently until just combined.
6. Spray muffin pan with nonstick spray or use paper muffin pan liners. Divide batter to make 12 muffins, about 1/4 cup batter each.
7. Bake 20 minutes or until golden brown.
8. Sprinkle with confectioner's sugar, if desired. (After cooling).