1Strain the liquid from the ricotta using cheesecloth to prevent the dip from being runny. Place several layers of cheesecloth in a strainer and add the ricotta. Let drain for at least 20 minutes before squeezing by hand to remove the excess liquid.
2Add the strained ricotta, mascarpone, powdered sugar, vanilla extract, and orange zest to a mixing bowl. Beat with a paddle until just combined.
3Mix in the chocolate chips and, if desired, the chopped pistachios. Transfer to a serving bowl and sprinkle a few more mini chocolate chips and pistachios on top. Chill until ready to serve.
4Serve with cannoli shells or chips, waffle cones, or graham crackers.