In a food processor, process together the flour, baking powder, sugar, and teaspoon salt. Pulse in cold butter, Add 1 egg and 1 teaspoon vanilla. Mix until dough forms. Roll into 2 - 9” inch crust. Place dough in greased pie plates. Chill in freezer for 1 hour.
Bring the water to a boil in a saucepan, and stir in the rice. Reduce the heat to medium-low, cover, and cook for 20 minutes. Stir in the milk. Continue cooking, stirring frequently, until the mixture thickens. Set aside to cool.
Preheat oven to 325 degrees F (165 degrees C).
Meanwhile, beat the ricotta cheese, 1 cups sugar, lemon juice, lemon zest, and 6 eggs together in a mixing bowl until smooth and frothy. Stir in the cooled rice and pineapple mixture until evenly blended. Pour into the pie shells.
Bake pies in preheated oven until the filling is set and tops are golden brown, about 90 minutes. Cool on racks.