Preheat the oven to 350°F and line an 8x8 inch baking pan with parchment paper, leaving an overhang. Mix the almond flour, powdered sweetener, cinnamon, salt and melted butter, press firmly into the pan and bake for 10 minutes. Reduce the oven to 325°F.
Beat the cream cheese, drained ricotta and powdered sweetener for 2 to 3 minutes, until very smooth and creamy.
Mix in the vanilla, orange zest and cinnamon, then add the eggs one at a time on low speed just until combined. Fold in 1/4 cup mini chocolate chips.
Pour the cannoli filling over the crust and smooth the top. Bake for 32 to 36 minutes, until the edges are set and the center has only a slight jiggle.
Cool for 1 hour at room temperature, then chill for at least 4 hours so the ricotta filling firms up fully.
Scatter the remaining mini chocolate chips and the chopped pistachios over the top and dust lightly with powdered sweetener.
Lift out using the parchment and slice into 16 bars.