Cheesecake al Limoncello

Crust :
1/4 cup (1/2 stick) butter, melted
1 cup graham cracker crumbs
1/2 cup vanilla wafers or hazelnut cookies
2 tablespoons granulated sugar

Batter:
32 ounces cream cheese
1 1/2 cups granulated sugar
4 tablespoons flour
1/4 teaspoon salt
1/2 tablespoon lemon zest
4 eggs
1/2 cup limoncello

Topping:
2 cups sour cream
1/4 cup granulated sugar
1 teaspoon limoncello

Crust: Crumb the cookies, mix with the graham cracker crumbs and melted butter, and press the mixture in the bottom and about an inch up the sides of a 9 1/2-inch springform pan.

Batter: Beat together the cream cheese and sugar until smooth and fluffy. Add the eggs one at a time without excessive beating to avoid removing the air, followed by mixing in the remaining batter ingredients. Pour into the pan and bake at 350 degrees F for about an hour or until the center of the surface is somewhat solid. Remove from the oven and let rest 10 minutes.

Topping: Mix together the sour cream, sugar and limoncello and spread evenly over the top. Bake another 10 minutes; remove and let cool to room temperature.

Refrigerate at least 12 hours before serving.