Sicilian Ricotta Cheese Cake

32 ounces ricotta cheese drained
1 orange for 2 teaspoons orange zest/grated rind
1/3 cup flour
1 cup sugar
6 eggs
1 teaspoon vanilla extract
18 graham crackers 2 packets from a 14 ounce box
1 stick or 4 ounces butter
2 tablespoons powdered sugar for dusting

Instructions