A favorite of Emilia-Romagna, these ricotta fritters usually appear as part of the array of Carnival treats found at this time of year.
I took inspiration from Roman food writer Ada Boni's Italian Regional Cooking. Her castagnole recipe is extremely basic (I added sugar and citrus to the mixture), but I like that she calls only for a little flour, as many of today's recipes use half ricotta and half flour for a more solid fritter.
There are so many was to play with this recipe: Take out the orange and/or lemon, use an aniseed (or any other) liqueur instead of rum, add vanilla, or substitute confectioners' sugar instead of granulated sugar. I often see this recipe with baking powder too, which makes them puff up more and become spongier -- but they remain much more delicate without it.
You can also bake these if you prefer not to deep fry, though they do come out crunchier. —Emiko
Mix all of the ingredients together, except for the oil, in a mixing bowl until well combined.
Over low heat, heat a small saucepan with enough oil for the fritters to float. Test the heat by dropping a cube of bread or a small blob of ricotta mixture into it. You should immediately see little bubbles appear all around the bread. With the help of 2 spoons, drop tablespoon-sized blobs of the ricotta mixture into the hot oil, and fry until evenly golden-brown, about 90 seconds. You can fry several at a time, but don't overcrowd the pan or the temperature will drop too much.
Drain on paper towels and, while still hot, roll the fritters in extra sugar to coat. Serve warm or cold.