If the ricotta is very watery, place it in a sieve and let drain for 30 minutes.
Place the ricotta in a mixing bowl, then add the sugar, coffee and, if using, the liqueur. Whisk vigorously until you have a perfectly smooth, fluffy mixture.
Taste and adjust for flavor. Add amore coffee, sugar or rum, if you like, to suit your taste. Or if you find the taste too strong, add more ricotta.
Let the mixture chill in the fridge for at least an hour.
When you're ready to eat, spoon the mixture into demi-tasse cups and top each with indicated toppings to your liking. Ricotta al caffè pairs beautifully with cookies or wafers.