Special equipment: a 10-inch springform pan
For the crust: Preheat the oven to 325 degrees F. Place an oven rack in the center position, without any racks above it.
Place the cookies in a food processor; pulse to the texture of sand. Add the crushed cookies to a 10-inch springform pan and pour in the melted butter. Using your hands, mix together the cookie crumbs and butter until they are completely combined and hold together when pinched. Firmly press the cookie crust into the bottom of the pan. Press down on the crust with the bottom of a cup to ensure it is tightly packed.
Bake the crust for 12 to 14 minutes, or until golden brown all over. Remove from oven and let cool. When the pan is cool enough to handle, wrap it in foil three-quarters of the way up the sides of the pan--this will prevent any water from getting into the cheesecake while it is baked in a water bath.
For the cheesecake: In a stand mixer fitted with the paddle attachment, add the cream cheese, granulated sugar, sour cream, eggs, lemon juice, lemon zest, vanilla extract and salt. Slowly turn the mixer up to medium-high speed; continue to mix for 2 minutes, until the ingredients are completely combined and smooth.
Set aside 1/4 cup of the lemon curd and reserve it for the topping. With a rubber spatula, fold the remaining lemon curd into the cheesecake mixture. Pour the mixture over the cooled crust and spread it evenly, making sure to flatten the top. Gently tap the pan a few times on a flat surface to even out the mixture.
Use the reserved lemon curd to make a fun design in the top of the cheesecake. For instance, you can dollop 15 small dots, about a heaping 1/2 teaspoon each, around the border of the cake and then 6 small dots towards the center of the cake and 1 dot directly in the center. Drag a skewer around the center of the first ring of dots to pull the lemon curd into a teardrop shape. Repeat with the interior circle of lemon curd drops.
Place the foil-lined springform pan in a large roasting pan. Fill the roasting pan with hot water until it reaches about 1 inch up the sides of the pan. Bake the cheesecake for 55 to 60 minutes, until the edges are set but the center still has a pudding-like jiggle. Remove from the oven and let sit 10 minutes before removing the pan from the water bath. Let the cheesecake sit another 30 minutes. While the cheesecake is still warm, run a paring knife around the inside edge of the pan and then release the sides of the pan. (If you do this after the cheesecake has cooled completely, the cake may tear slightly.) Let the cheesecake cool completely before slicing and serving. Refrigerate any cheesecake not being served immediately.
Preheat the oven to 350 degrees F. Line a 13-by-9-inch baking pan with foil, leaving a 2-inch overhang on two sides. Lightly grease the foil and sides of the pan with butter.
In a food processor, pulse the sugar with the lemon zest and rosemary until well combined. Remove 2 tablespoons of the sugar mixture and reserve.
Add the butter, vanilla and salt to the food processor with the sugar and pulse until combined. Add the flour, about 1 cup at a time, pulsing to combine after each addition. After the last addition, you may have to stir and scrape down the sides of the food processor to help incorporate all of the flour. Continue to pulse until the dough comes together.
Turn the dough out into the prepared baking pan and press it in evenly. Poke the dough all over with a fork and sprinkle it with the reserved sugar.
Use a knife to cut the dough into approximately 3-by-1-inch rectangles (or whichever shape you prefer). Bake until golden brown at the edges and golden in the center, about 25 minutes. As soon as the cookies come out of the oven, use a bench scraper or knife to re-cut the lines of the cookies. Cool in the pan for 15 minutes, then carefully remove the cookies with the foil and cool completely on a rack.
It is very important to make sure the cream cheese, sour cream and eggs are all at room temperature. If they aren't, you will notice small dots in the filling that won't smooth out when mixed. The cheesecake will still bake up just fine, but the dots will change the texture slightly.