Put ricotta in a large fine sieve set over a large bowl; let drain 20 minutes. Discard liquid. Transfer ricotta to a serving bowl. Stir in sugar until smooth. Fold in chocolate. Ricotta mixture can be refrigerated, covered, up to 8 hours. Stir in nuts or raisins, if desired, before serving. Serve with biscotti and fruit.
I love this recipe. Super easy, just sweet enough. I always make it the day after we finish a lasagne, out of the leftover ricotta.