Place the ricotta cheese and sugar in the bowl of a stand mixer fitted with the paddle attachment. (If you don't have a stand mixer, you can put the ingredients in a bowl and use a hand mixer with the blending attachments.) Mix on slow speed just until the ingredients are blended together, a few seconds, then raise the speed to medium-low and continue to mix until smooth, about 1 additional minute. You are looking for the sugar to help break down the cheese and for the sugar to dissolve.
Once the mixture is smooth, add the pumpkin puree and pumpkin pie spice. Allow the mixture to fully combine on medium speed. Once the mixture is smooth, add the chocolate chips and stir by hand to combine. Place the mixture in the refrigerator until ready to serve.
Put the carved pumpkin on a display plate. Place the top of the pumpkin back on top. Spoon the cannoli dip into the mouth of the pumpkin and out onto your display plate. Sprinkle the dip with white chocolate chips. Arrange the chips around the dip and serve.