Prep the pan and oven. Heat your oven to 325°F (163°C).
Wrap the outside of the springform pan with foil to prevent leaks. Lightly mist the inside with nonstick spray.
Make the crust. Mix graham crumbs, almond flour, sweetener, cinnamon, and salt. Stir in melted butter until it looks like damp sand.
Press firmly into the bottom of the pan using the bottom of a glass. Bake for 8 minutes, then cool while you make the filling.
Beat the cream cheese. In a large bowl, beat light cream cheese with the sweetener until smooth and fluffy, about 2 minutes. Scrape the bowl so there are no lumps.
Add yogurt and vanilla. Mix in Greek yogurt, vanilla, cornstarch, and a pinch of salt.
Beat just until combined and silky.
Finish with eggs. Add eggs one at a time, mixing on low until just incorporated. Do not overmix—that can add too much air and cause cracks.
Pour and smooth. Pour the batter over the cooled crust. Tap the pan gently on the counter to release any air bubbles.
Create a gentle bake. Place the pan on a sheet pan. Add a separate small baking dish with hot water to the oven to create steam.
Bake 35–40 minutes, until the edges are set and the center still has a slight wobble.
Cool gradually. Turn off the oven, crack the door, and let the cheesecake sit for 30 minutes. Then move it to a rack to cool to room temperature.
Chill. Cover and refrigerate at least 4 hours, preferably overnight, for a clean slice and best texture.
Make the light salted caramel. In a small saucepan over medium heat, warm the sweetener until it dissolves and starts to deepen slightly in color. Add butter and whisk.
Slowly whisk in the milk. Simmer 6–8 minutes, stirring, until slightly thick and glossy. Remove from heat, stir in vanilla and add salt to taste.
Let cool to room temperature; it will thicken as it cools.
Finish and serve. Unclip the cheesecake, slide onto a plate, and spoon the cooled caramel over the top. Sprinkle with flaky sea salt. Slice with a warm knife for clean edges.