Using a hand mixer, whip the mascarpone cheese until fluffy, then mix in the pumpkin and ricotta until well combined.
Add the powdered sugar, vanilla, cinnamon and miniature chocolate chips then mix well to combine.
Spoon the filling into a piping bag or Ziploc bag and cut off the tip.
Fill the cannoli shells, then dip the ends into and then chocolate chips.
To make chocolate glaze, add the 1/3 cup chocolate chips and butter to a microwave-safe bowl. Microwave at 30 second intervals, stirring after each until the mixture is smooth. Spoon the glaze over the cannoli and allow to set. Serve immediately.