Butter to grease pan
2 15-ounce containers ricotta
1 cup sugar plus extra for pan
1 teaspoon vanilla
3 tablespoons orange zest (about 2 oranges)
Preheat oven to 350 degrees.
Prepare a 9-inch springform pan (10-inch can work as well).
Lightly butter the inside and shake some sugar around to adhere to the butter.
In a large bowl whisk together the ricotta and sugar until smooth. Whisk in eggs one at a time until each is well incorporated. Add vanilla and orange zest (reserve some zest for garnish), whisk in.
Pour batter into pan and bake at center of oven. Bake for one hour until the cake is set, the edges are golden, and a toothpick in the center comes out clean. Let cake cool in pan, then remove from pan and refrigerate for about an hour before serving.