Preheat oven to 350 F.

1. Spray 3″ metal rings, small cake pans or large muffin pans with cooking spray.
2. In mixer with paddle attachment, whip together butter and sugar until fluffy.
3. Add eggs one at a time, beating well after each addition.
4. Sift together flour, baking powder and salt into a medium bowl. Sift in cornmeal. Add sifted ingredients to butter mixture and beat just until blended.
5. Mix in lemon zest.
6. Using a #12 scoop, divide the batter into the prepared rings/pans, flattening out the top with a spoon so it is level in the cup.
7. On top of each cake, sprinkle 1 tsp. sanding sugar and press in 3 grapes  so they are just popping out of the top.
8. Place cups/dishes on sheet pan and bake for 28 minutes until slightly browned on top.
9. Cool cakes.