Prep the pan and oven: Heat the oven to 325°F (165°C). Lightly grease a 9-inch springform pan.
For extra insurance, line the bottom with parchment.
Make the crust: Stir graham crumbs, sugar, salt, and melted butter until evenly moistened. Press firmly into the bottom and slightly up the sides of the pan. Use the bottom of a measuring cup for a compact, even layer.
Par-bake the crust: Bake for 8–10 minutes until just set and fragrant.
Cool on a rack while you make the filling.
Blend the cottage cheese: Add cottage cheese to a blender or food processor. Blend until completely smooth and glossy, 60–90 seconds. Scrape down the sides to catch any curds.
This step is key to a creamy texture.
Cream the cheeses: In a large bowl, beat softened cream cheese with sugar on medium speed until smooth, 1–2 minutes. Avoid whipping too much air into the mixture.
Combine: Beat in the pureed cottage cheese, lemon zest, lemon juice, vanilla, salt, and cornstarch until just smooth. Stop and scrape the bowl as needed.
Add the eggs: Beat in the eggs one at a time on low speed, just until incorporated.
Overmixing leads to cracks, so keep it gentle.
Fill and smooth: Pour the batter into the cooled crust. Tap the pan a few times on the counter to release air bubbles. Smooth the top with a spatula.
Bake low and slow: Bake at 325°F for 45–60 minutes.
The edges should be set and the center should have a slight wobble, like set Jell-O. If the top is browning too quickly, tent loosely with foil.
Cool gradually: Turn off the oven, crack the door, and let the cheesecake rest inside for 30 minutes. Then move it to a cooling rack until room temperature.
Chill to set: Cover and chill at least 6 hours, preferably overnight.
This step firms the texture and deepens the lemon flavor.
Serve: Run a thin knife around the edge before unlatching the pan. Top with sour cream or yogurt and berries if you like. Slice with a hot, dry knife for clean edges.