Prep the pan and oven. Heat the oven to 325°F (163°C). Line the bottom of a 9-inch springform pan with parchment and lightly grease the sides.
Wrap the outside of the pan with a double layer of foil if you plan to use a water bath.
Make the crust. In a bowl, combine 2 cups almond flour, 4 tablespoons melted butter, 3 tablespoons granulated keto sweetener, 1 teaspoon vanilla, and a pinch of salt. Mix until it resembles damp sand. Press evenly into the pan, going slightly up the sides.
Par-bake the crust. Bake for 10–12 minutes until just golden and set.
Cool on a rack while you make the filling.
Soften the cream cheese. In a large bowl, beat 24 ounces of cream cheese on medium until smooth and no lumps remain, about 2 minutes. Scrape the bowl as needed.
Sweeten and smooth. Add 3/4 cup powdered keto sweetener (or granulated), 1/2 cup sour cream, 2 teaspoons vanilla, and a pinch of salt. Beat on low-medium until silky.
If using, bloom 1 teaspoon gelatin in 2 tablespoons cold water; warm gently until melted and whisk into the batter.
Add eggs last. Beat in 3 large eggs, one at a time, on low speed. Mix just until combined. Overmixing can add air and cause cracks.
Fill and level. Pour the batter over the crust.
Tap the pan lightly on the counter to release any bubbles. Run a spatula across the top to smooth.
Bake gently. Place the pan on a baking sheet. For the most even texture, set the pan in a larger roasting pan and pour hot water halfway up the sides (water bath optional but recommended).
Bake 50–60 minutes, until the edges are set and the center still has a slight wobble.
Cool slowly. Turn off the oven, crack the door, and let the cheesecake rest inside for 1 hour. Then remove, run a knife around the edge, and cool to room temperature. Chill at least 6 hours, preferably overnight.
Make the keto caramel. In a medium saucepan, combine 1/2 cup unsalted butter and 3/4 cup allulose over medium heat.
Stir as it melts and turns a deeper golden color, 5–7 minutes. Whisk in 1/2 cup heavy cream slowly, plus 1 teaspoon vanilla and a pinch of salt. Simmer 3–5 minutes until slightly thick.
It will thicken more as it cools.
Cool the caramel. Let the caramel sit until it’s pourable but not hot—about body temperature. If it’s too thin, simmer another minute. If too thick, whisk in a teaspoon of cream.
Release and drip. Remove the chilled cheesecake from the springform.
Place on a serving plate. Spoon caramel along the edges to create drips, then spread a thin layer over the top. Chill 15–20 minutes to set.
Serve. Slice with a hot, clean knife.
Wipe the blade between cuts for neat slices. Add a sprinkle of flaky sea salt on top if you like a salted caramel vibe.