To prepare dough: combine all ingredients in mixing bowl. Knead dough and roll with rolling pin to form thin layer.
To prepare filling: Preheat oven to 300 degrees. In a large bowl, combine ricotta, cooked rice, eggs, salt, sugar, and vanilla extract. Line ovenproof dish, or pie plate, with the dough, reserving any extra dough. Place filling in dough. Use leftover dough to decorate top of cake. If using dough on top, sprinkle with cake decorations. Bake for 40 minutes. Cake is done when toothpick inserted in the center comes out dry.