"Bettina" might not approve of putting ricotta cheese to use in desserts, and usually it is too expensive for us to recommend it as a frugal ingredient; but our local supermarket occasionally runs specials on an Italian-style brand of dairy products--their Parmesan, their ricotta and so on--and that's when we pick some up.
We haven't made frozen Tortoni for awhile, but we do sometimes make Cocoa Ricotta Cream when we have a container of cheese on hand. It's very good, but you don't want it after a heavy meal--ricotta desserts aren't usually sweet, but they are rich.
Tonight we had one of those sale-priced 2-cup containers in the fridge, and Father's Day company coming (just Grandpa Squirrel, but he's important), and strawberries and raspberries to make shortcake with, but no whipped cream. We could have used plain yogurt, or just had the fruit on top of the plain biscuit cake, but there was the ricotta, and Mama Squirrel remembered a recipe for Ricotta Topping in the Goldbecks' American Wholefoods Cuisine. So that's what we did. Short version: run the ricotta cheese plus some yogurt plus some honey plus a little vanilla through the food processor, or beat with electric beaters until fluffy. The recipe also called for a bit additional cream cheese, but that seems optional if your ricotta is already pretty creamy.
An option to make all this more frugal would be to use a homemade version of ricotta cheese, like the Hillbilly Housewife's version. I've made it and used it in main dishes, but haven't yet tried it in desserts. If I do, I'll let you know.