Preheat your oven to 425°F. Arrange the tart shells on a baking sheet.
In a small bowl, mix together the granulated sugar and cinnamon. Brush the shells with melted butter, then sprinkle them with the cinnamon sugar mixture.
Bake the shells until they're golden brown, which should take about 8 minutes. Let them cool down.
While the shells are cooling, whisk together the ricotta cheese, powdered sugar, orange zest, and vanilla until smooth. Transfer the mixture to a zip-top plastic bag, seal it, and refrigerate until you're ready to use it.
Once the shells are cooled, arrange them on a platter. Snip off a small corner of the plastic bag and pipe the filling into each shell.
Top the filled shells with chocolate chips or pistachios, and dust them with powdered sugar.
Enjoy your delightful mini cannoli bites!