Gather the ingredients.

To make the filling: Beat eggs, sugar, and vanilla together in a large bowl. Stir in ricotta cheese and chocolate chips; set aside.

To make the crust: Combine flour, sugar, and baking powder together in a large bowl; cut in shortening until mixture resembles coarse crumbs. Mix in beaten eggs and vanilla.

Divide dough into 4 balls, wrap in plastic, and chill for at least 30 minutes.

Preheat the oven to 325°F (165°C). Grease two 9-inch, deep-dish pie plates.

Roll out two dough balls and line the bottom and sides of each prepared pie plate. Avoid making the crust too thick as it will expand during cooking.

Roll the remaining two dough balls out into 10-inch circles. Cut into 1/2-inch strips with a sharp paring knife or pastry wheel.

Pour ricotta filling evenly into pie crusts. Use the dough strips to create a lattice pattern over each pie, folding and fluting as needed. Brush the lattice top with milk.

Bake in the preheated oven for 20 to 30 minutes; remove foil.

Rotate pies on the rack and continue baking until a knife inserted in the center comes out clean, about 25 to 30 minutes more.