Preheat your oven to 350°F. Brush a 9-inch pie plate with half of the butter. Cover the bottom with a parchment paper circle and brush it with the remaining butter.
In a medium mixing bowl, whisk the ricotta, sweetener, vanilla, cornstarch, and lemon zest.
Add the eggs and whisk just until combined. Don't overmix.
Pour the batter into the prepared pie plate. Bake until the cake is set, about 45 minutes. When done, the sides will be puffed and browned. The center will be firm to the touch but jiggly underneath.
Cool the cake for 2 hours in the pan on a cooling rack, then cover and refrigerate it for at least 2 more hours, preferably overnight.
Slice the cake. Place the slices on paper towels to absorb any extra moisture.
Store the leftovers in a sealed container in the fridge for 3-4 days on paper towels to absorb moisture. Replace the paper towels at least once a day - they will become soaked.
Video
Notes
The lemon zest is a must. Sometimes it’s optional, but not in this recipe.
Add the eggs at the end, and don’t over-mix the batter. You don't want to introduce too much air into the batter.
All ingredients should be at room temperature, so remove them from the fridge 2 hours before you start making the cake.
The batter will reach the top of the baking dish, so make sure to grease the sides all the way to the top.
Please use whole-milk cheese in this recipe, not reduced fat.
The nutrition info assumes that stevia and cornstarch were used.
This cake actually improves after a day or two in the fridge. The paper towels soak up extra liquid, and it becomes creamier.
Sweeteners that work in this recipe are granulated sugar, erythritol, or stevia. I don't recommend using honey (or any liquid sweetener other than stevia) or coconut sugar.
Plan ahead: Like all cheesecakes, this cake needs time to chill and set after it's baked, so plan accordingly. If you need it by the evening, you'll need to start making it in the morning. Or make it the day before.