- Preheat oven to 325°. 
- Stir together ricotta and 6 eggs until smooth. 
- Stir in sugar, vanilla, heavy cream, milk and cinnamon. 
- Set aside filling. 
- In medium mixing bowl, combine flour, baking powder and sugar. 
- Cut in butter with pastry blender until chunks resemble coarse crumbs. 
- Mix in lightly beaten eggs and vanilla extract just until incorporated. 
- Divide dough in half, wrap tightly in plastic and refrigerate for at least 30 minutes. 
- Roll out dough to fit into 2 greased pie plates. 
- (Not too thick though, because this dough will expand due to the baking powder and eggs.) 
- The dough is crumbly so I don't suggest fluting the edges. 
- Pour the ricotta filling evenly into both pie pans. 
- Shield edges of crust all the way around with foil and place pies in the oven. 
- Bake for 30 minutes, then remove foil and rotate pies if needed so they cook evenly. 
- Bake an additional 30 - 45 minutes, until crust is golden and a sharp knife inserted in the center comes out clean. 
- Cool completely, then refrigerate before serving. 
- Optional: garnish with whipped cream and lemon zest if desired.