Prep the pan and oven: Preheat the oven to 325°F (165°C). Lightly spray a 9-inch springform pan with nonstick spray. If you plan to use a water bath, wrap the outside of the pan with a double layer of foil.
Make the crust: In a bowl, mix graham crumbs, sugar or sweetener, melted light butter or coconut oil, salt, and optional coconut.
It should look like damp sand. Press firmly into the bottom of the pan in an even layer. Bake for 8–10 minutes, then let it cool slightly.
Drain the pineapple: Place crushed pineapple in a fine mesh sieve or a clean kitchen towel.
Press or squeeze out as much liquid as possible. Excess moisture will crack or loosen the filling, so take a minute here.
Blend the filling base: Beat softened cream cheese on medium until smooth and fluffy, about 1–2 minutes. Add Greek yogurt and beat again until creamy, scraping the bowl as needed.
Sweeten and stabilize: Add sugar, sweetener, vanilla, lemon juice, cornstarch, and a pinch of salt. Mix on low until combined. Don’t overbeat or you’ll whip in too much air.
Add eggs: Beat in the eggs one at a time on low speed just until incorporated.
The batter should be silky and pourable.
Fold in pineapple: Gently fold the well-drained crushed pineapple into the batter with a spatula.
Pour and smooth: Pour filling over the crust and smooth the top. Tap the pan gently on the counter to pop surface bubbles.
Bake: Place the pan on a middle rack. For extra insurance against cracking, set the pan inside a larger pan and pour hot water halfway up the sides.
Bake for 45–55 minutes, until the edges are set and the center still has a slight jiggle.
Cool gradually: Turn off the oven, crack the door, and let the cheesecake rest inside for 30 minutes. Then transfer to a rack and cool to room temperature.
Chill: Cover and refrigerate at least 6 hours, preferably overnight. Chilling firms the texture and deepens the flavor.
Serve: Run a thin knife around the edge before releasing the springform.
Add a spoonful of drained pineapple or a light swirl of whipped topping if you like. Slice with a warm, clean knife for neat edges.