Drain the Ricotta
Place the ricotta cheese in a fine-mesh strainer or wrap it in cheesecloth.
Allow it to drain over a bowl in the refrigerator for at least 2 hours or overnight. This step is crucial for achieving a thick, creamy filling.
Mix the Base
In a medium mixing bowl, combine the drained ricotta and powdered sugar. Use a whisk or electric hand mixer to blend until smooth.
Add Flavorings
Stir in the vanilla extract, orange or lemon zest (if using), and a pinch of ground cinnamon for added warmth.
Incorporate Mix-Ins
Fold in mini chocolate chips or chopped nuts if desired. These add texture and enhance the flavor of the filling.
Chill the Filling
Cover the bowl with plastic wrap and refrigerate for at least 1 hour to allow the flavors to meld and the filling to firm up.
Fill and Serve
Transfer the filling to a piping bag or resealable plastic bag with the tip cut off. Pipe into prepared cannoli shells or use the filling as desired in your favorite desserts.