For Shortbread Crust:
1/2 cup unsalted butter (room temperature)
1/4 cup granulated sugar
1/2 cup flour
1/2 cup finely ground shortbread cookies
For Cheesecake Filling:
2 pounds cream cheese
1 cup mascarpone cheese
1 1/2 cups sugar
2 eggs
2 1/2 teaspoons lemon zest, or more to taste
2 tablespoons fresh squeezed lemon juice, or more to taste
Sour Cream Topping:
1/2 cup sour cream
1/4 cup granulated sugar
To Make Crust:
Preheat oven to 350 degrees F. Wrap aluminum foil around bottom and sides of a 9-inch springform pan.
Using an electric mixer, cream the butter and sugar together on medium high speed for 3-4 minutes. Add flour and ground shortbread cookies to the mixture and blend for 3-4 seconds until fully incorporated. Press the mixture evenly into the bottom of springform pan. Bake the crust at 350° F for 20-25 minutes, or until golden brown. Allow the crust to cool completely.
To Make Cheesecake Filling:
Using an electric mixer, beat the cream cheese until light and smooth. Add the mascarpone cheese and sugar and continue to beat on medium speed. Add the eggs one at a time. Blend in the lemon zest and juice. Pour mixture into the cooled crust.
Set the cheesecake pan into a roasting pan, and add enough water to the roasting pan to reach halfway up sides of the cheesecake pan. Place in a 350° F oven for approximately one hour or until the cake is set (may need to bake an extra 20 to 30 minutes depending on your oven), and the top is golden brown. Remove the cheese cake from the roasting pan and place on a wire rack. Allow cheese cake to cool slightly, then place in the refrigerator for 6 hours or overnight.
Sour Cream Topping
In a medium bowl, mix together the sour cream and sugar. Spread over top of cheesecake 10 minutes before the cake is done.
Makes: 12-16 servings.