Preheat oven to 425F (220C)
Rub the lemon zest into the sugar to release the lemon oils. Doing this will add a more intense lemon flavor.
In a large mixing bowl, combine softened cream cheese and lemon sugar. Mix until smooth.
Next, add the eggs one at a time, making sure to mix well after each addition.
Slowly pour in heavy cream while mixing.
Sift in the cornstarch and salt, then mix until well combined.
Line a muffin tin or ramekin with a 4x4 square parchment paper. Pour in the batter up to the rim.
Place in the center rack of the oven and bake for 30 minutes. At this point, the top of the cheesecake should be brown. If it is not, you can choose to bake it for a few minutes longer or place it under the broiler until it reaches your desired color. Remove then set aside to cool completely.
Once the mini cheesecakes have cooled, carefully pour the lemon curd in the center and serve!