Preheat the oven to 325 degrees. Coat the inside of a 9-inch springform pan with cooking spray.
Place the ricotta cheese in a strainer set over a bowl and let stand for 15 minutes, stirring occasionally, to drain off excess moisture.
Place the egg whites in a large mixing bowl and beat on high speed with an electric mixer fitted with a whisk attachment until the whites just hold stiff peaks. Do not overwhip. The whites should look smooth, not grainy.
Combine the egg yolks and granulated sugar in another large mixing bowl and beat on high speed until pale yellow, about 5 minutes. Stir in the ricotta, vanilla, lemon zest, cinnamon, and nutmeg until just combined. Fold the egg whites into the ricotta mixture with a rubber spatula. Place the prepared springform pan on a baking sheet and pour in the filling.
Bake the cheesecake until it is deep golden brown and pulling away from the sides of the pan, about 1 hour and 20 minutes. As soon as the cake is out of the oven, run a sharp paring knife around the edge of the pan to separate the cheesecake from the sides of the pan. Transfer the pan to a wire rack and let the cheesecake cool completely. Cover it with plastic wrap and refrigerate it until serving, at least 6 hour and up to 1 day.
Before serving, remove the sides of the pan and dust with confectioners’ sugar. Makes 8 to 10 servings.
Mom’s Big Book of Baking.