1. Place colander in a 2-quart glass measuring cup or medium bowl. Line colander with 3 layers of cheesecloth, allowing cheesecloth to extend over outside edges. Spoon ricotta cheese into colander. Gather edges of cheesecloth; tie securely. Refrigerate 12 hours. Spoon drained cheese into a large bowl; discard liquid.
2. Add powdered sugar, cream cheese, cornstarch, lemon rind, vanilla, and cinnamon to drained ricotta; beat with a mixer at medium speed until combined. Fold in chocolate minichips; cover and chill until ready to assemble cannoli.
3. Spoon ricotta mixture into a pastry bag fitted with a 1/2-inch round tip. Pipe 1 tablespoon into each end of prepared cannoli shells. Serve immediately.