Dip the cannoli ends in melted white chocolate, and line on a wire rack to drain off any excess. Sprinkle with red and green sprinkles, and let cool to harden the chocolate.
In an electric mixer fitted with a paddle attachment, blend together the ricotta, cream cheese, powdered sugar, and peppermint extract until smooth.
Pipe the filling into the cannoli shells, and keep cool until ready to serve.
Tips: Lightly grease the rack with pan-release spray before draining off the chocolate from the cannolis—this will keep the cannolis from sticking. If you have a couple that stick, carefully pop them free using a warm butter knife. (You can warm the knife by running it under hot water).