Prep the pan. Wrap the outside of a 9-inch springform pan with two layers of heavy-duty foil to prevent leaks. Line the bottom with a circle of parchment. Preheat your oven to 325°F (163°C).

Make the crust. In a bowl, mix 1 1/2 cups almond flour, 3 tablespoons powdered allulose or erythritol, a pinch of salt, 1/2 teaspoon vanilla, and 5 tablespoons melted butter until it looks like damp sand.

Par-bake the crust. Press the mixture firmly into the bottom of the pan. Bake for 10 minutes, then cool while you make the filling. Reduce oven temp to 300°F (150°C).

Beat the cream cheese. In a large bowl, beat 32 oz softened cream cheese on medium speed until completely smooth and fluffy, about 2 minutes. Scrape the bowl and beat again. Smooth cream cheese is key to a silky texture.

Add sweetener and flavor. Add 3/4 to 1 cup powdered allulose or erythritol (adjust to taste), 1 teaspoon vanilla, a pinch of salt, and 1 teaspoon lemon zest (optional). Beat on low until combined to avoid air bubbles.

Blend in cream and sour cream. Add 1/3 cup heavy cream and 1/2 cup sour cream. Mix on low until just smooth. Scrape the bowl well. Do not overmix.

Add the eggs. Add 4 large eggs, one at a time, mixing on low after each addition just until blended. The batter should be thick and glossy with minimal bubbles.

Fill the pan. Pour the batter over the cooled crust. Tap the pan gently on the counter a few times to release any trapped air.

Set up the water bath. Place the foil-wrapped pan in a large roasting pan. Pour hot tap water into the roasting pan until it reaches about halfway up the sides of the springform. This helps prevent cracks and keeps the texture creamy.

Bake low and slow. Bake at 300°F (150°C) for 60–70 minutes. The edges should be set, and the center should still wobble slightly like Jell-O.

Turn off and rest. Turn off the oven, crack the door, and let the cheesecake rest inside for 45–60 minutes. This gentle cool-down prevents sinking and cracking.

Cool completely. Remove from the water bath, unwrap the foil, and cool to room temperature. Run a thin knife around the edge to loosen.

Sour cream topping (optional, but classic). Mix 3/4 cup sour cream with 2–3 tablespoons powdered sweetener and 1/2 teaspoon vanilla. Spread gently over the cooled cheesecake.

Chill overnight. Cover and refrigerate at least 6 hours, preferably overnight. New York style is best fully chilled and set.

Slice and serve. Use a hot, clean knife for each cut. Garnish with a few berries or a drizzle of sugar-free sauce if you like.