Preheat oven to 400 degrees F. In a large bowl, stir to combine the ricotta, mascarpone, vanilla extract and powdered sugar until smooth. Transfer to a piping bag fitted with a large star tip and refrigerate until ready to use.
On a lightly floured surface, roll thawed pie dough into a thin round. Use a 2 1/2 -inch round cutter to cut out circles. Press rounds into the bottom and up the sides of an ungreased mini muffin tin. Spray the pie dough lightly with cooking spray and bake until golden and crisp, about 12-15 minutes. Let cool completely.
In a small bowl, microwave to melt 1 cup mini chocolate chips with vegetable oil, stirring to combine well. Working one at a time, dip the cooled pie shells into the chocolate, coating the top rim and letting excess drip off. Transfer to a wire rack fitted over a sheet tray and sprinkle edges with pistachios or sprinkles. Leave a few with plain chocolate. Let chocolate dry, about 15-20 minutes.
Fill shells with cannoli filling, piping into a star shape, and top with pistachios, sprinkles and mini chocolate chips.