Prep the pan: Line the bottom of a 9-inch springform pan with parchment. Lightly spray the sides with nonstick spray.
Preheat oven to 325°F (160°C).
Make the crust: In a bowl, combine crushed graham crackers, sweetener, salt, and melted butter. Stir until the crumbs look like damp sand. Press firmly into an even layer in the pan.
Bake for 8 minutes, then cool while you make the filling.
Beat the cream cheese: In a large bowl, beat light cream cheese until smooth and fluffy, about 1–2 minutes. This step helps avoid lumps.
Add yogurt and sweetener: Mix in Greek yogurt and sweetener until fully combined. Scrape the bowl to catch any bits stuck to the sides.
Flavor and thicken: Add vanilla, cornstarch, salt, and lemon juice if using.
Mix on low until just combined. Avoid overmixing to keep air out.
Finish with eggs: Add eggs one at a time, beating on low after each just until incorporated. The batter should be silky and pourable.
Fill and smooth: Pour the batter over the cooled crust.
Tap the pan lightly on the counter to pop surface bubbles. Run a spatula over the top to level.
Bake gently: Bake at 325°F (160°C) for 35–45 minutes. The edges should look set, and the center should have a slight jiggle the size of a quarter.
Do not overbake.
Cool slowly: Turn off the oven, crack the door, and let the cheesecake rest inside for 30 minutes. Then move to a rack and cool to room temp.
Chill to set: Cover and chill at least 6 hours, ideally overnight. This is when the creamy texture develops fully.
Make the strawberry topping: In a small saucepan, combine strawberries, sweetener, and lemon juice.
Cook over medium heat for 4–6 minutes, stirring, until juicy and soft. For a thicker sauce, stir in the cornstarch slurry and simmer 1 minute. Remove from heat and stir in vanilla.
Cool completely.
Top and serve: Release the springform ring, slide the cheesecake onto a plate, and spoon the cooled strawberry topping over the center. Slice with a hot, clean knife for neat edges.