cheese cake for Shavuos
I don't have any specific recipe, but I can tell you that ricotta-based cheesecakes are delicious and lighter than those based on cream cheese.
I checked in Joyce Goldstein's "Cucina ebraica" Cassola: ricotta soufflé pancake would be a good Shavuot sweet, as would "Crostata di ricotta e viscole": Cheese tart with sour-cherry preserves.
What other dairy dishes are you serving? If you want to lighten up your menu a bit, and you are of Ashkenazi descent, consider combining some of your traditional foods with others from Sephardic/Mediterranean traditions.