CRUST

1. Preheat your oven to 350ºF (177ºC) and line a 9×5 pan with parchment paper. Set aside.
2. Add the Graham Crackers or Digestive biscuits to a food processor or blender and crush them up into fine crumbs. Pour the crumbs into a bowl. Add in the melted butter. Use a fork to mix them together. It should all be wet and thickened.
3. Transfer the mixture to your lined pan. Spread it evenly and press the crust to the base firmly using the bottom of a spice jar. 
4. Blind bake the crust for 10-15 minutes at 350ºF  (177ºC). Allow it to cool for 5 minutes.  

LEMON CURD

1. Place the cubed butter and lemon zest in a large bowl.
2. Place a medium saucepan filled with two inches of water over medium low heat. In a medium bowl that serves as a double boiler, whisk together sugar, eggs and salt until combined. Slowly add the lemon juice and stir to incorporate.
3. Place the bowl over the pot with water and heat the curd over medium low heat, stirring often until the mixture thickens and coats the back of a spoon. Be sure to stir the curd evenly as it cooks, scraping the bottom and sides of the bowl as you go. The curd is done when the mixture is thick and the temperature measures 165ºF using an instant read thermometer.
4. Remove the curd from the heat and pour it through a fine mesh strainer into the bowl with the butter and lemon zest.
5. Whisk to combine well, stirring until all of the butter is melted and the curd is smooth.
6. Pour into a mason jar and allow to chill for atleast 4 hours or overnight.

CHEESECAKE FILLING

1. Preheat your oven to 325ºF (160ºC) after your crust is baked.
2. While the crust is baking, using an electric hand mixer or a stand mixer, beat the room temperature cream cheese until creamy. Add in the granulated sugar and beat until thoroughly combined.
3. Add in the sour cream or greek yogurt into the mixture and beat until the mixture is silky and creamy in texture.
4. Now stir in the lime juice and salt and beat until combined. Even though lime juice is optional, I highly recommend adding it for the best flavor.
5. Lastly, add in the eggs one at a time. Beat the mixture only until the eggs are incorporated. Be careful not to overbeat the mixture after adding eggs as this can cause air to go into your mixture resulting in a sunken cheesecake.
6. If your cheesecake batter is too runny at this point, I recommend chilling it in the refrigerator for 20 minutes before continuing. 
7. Pour the mixture over the pre-baked crust. Bake the cheesecake at 325ºF (160ºC) for 35-40 minutes or until the edges are completely set but the cheesecake is a bit wobbly in the center. Your edges will start to turn slightly golden brown when your cheesecake will be done.
8. Open your oven door slightly after baking the cheesecake and let it sit in the oven for about 10-15 minutes. You don’t want any sudden temperature changes which can cause your cheesecake to sink.
9.  Lastly, remove your cheesecake from the oven and let it cool completely on a wire rack.
10. Once cooled, pour lemon curd on top of the baked cheesecake. Bake the cheesecake at 325ºF (160ºC) for 10-15 minutes or until the lemon curd is set. Allow to cool completely again on a wire rack.
11. Transfer cheesecake to the refrigerator and let it chill for atleast 4 hours to overnight before slicing into bars.