Do this. Get some cheese cloth, a collander that you would normally drain pasta with or something else. Layer up the cheese cloth so that its a few layers thick, put the ricotta in and let the moisture drip out, every so often your going to want to take the ricotta out of the cheese cloth, ring out the cloth and reset the whole thing.
From here you have a few choices, you can get some cocoa powder, cocoa extract, vanilla extract, cinnamon extract, almond extract. Sugar free jello mix, sugar free pudding mix. Whatever it is and mix it in. You want to whip the mixture in a bowl until the ricotta increases in volume. Cover with wax paper or plastic wrap and move into your freezer for a while. Eat it when it starts to thicken up.
Its the process you would use to make cannoli cream.