In bowl, combine the ricotta cheese, eggs, chocolate chips, sugar, orange peel, and orange liqueur, if using.
Roll out 1/2 of the pastry to fit pie pan. Fill with ricotta mixture.
Roll out rest of pastry into an 11" circle. Cut into 1" wide strips. Lay half of the strips across the pie 1" apart. Fold back every other strip halfway. Lay another strip across center of pie at a right angle. Unfold strips over center strip. Fold back the alternate strips; place a second strip across the pie. Continue to add strips until pie is covered with lattice. Trim, seal, and flute the edges.
Bake at 425F for 40-45 minutes. Cool. Refrigerate leftovers.