Step 1

Preheat oven to 350 degrees F.

Step 2

Lightly grease the bottom and sides of a 9-inch springform pan.

Step 3

In a bowl, mix together the crumbs, butter, and 1 tablespoon of lemon zest.

Step 4

Press the crumb mixture over the bottom of the pan, and bake until golden brown, about 15 minutes.

Step 5

Cool crust completely.

Step 6

Wrap the bottom and sides of the pan in aluminum foil.In a bowl, beat the ricotta cheese with an electric mixer on medium speed until creamy.

Step 7

Add the cream cheese and sugar, and beat until smooth.

Step 8

Add the limoncello, extract, remaining lemon zest, and beat until blended.

Step 9

Add the eggs, one at a time.

Step 10

Pour the cheesecake mixture over the crumbs, and place the pan into a larger roasting pan.

Step 11

Pour enough hot water into the roasting pan until it comes halfway up the sides.

Step 12

Bake until the cheesecake is golden and the center still has a little wobble, about 1 hour.

Step 13

Let the cake sit until it cools to room temperature.

Step 14

To make the curd, whisk together the lemon juice, sugar and eggs until thoroughly blended.

Step 15

Pour the mixture into a small saucepan over low heat, whisking continually until the curd has thickened, about 5 to 7 minutes.

Step 16

Take the curd off the heat and whisk in the butter until smooth.

Step 17

Pour the curd through a fine strainer over the cheesecake.Refrigerate the cheesecake until it is cold, about 6 to 8 hours.