Prepare the pan: Line the bottom of a 9-inch springform pan with parchment. Lightly grease the sides.
Preheat oven to 325°F (163°C).
Make the crust: Mix 1 1/2 cups crumbs, 3 tablespoons sugar, a pinch of salt, and 6 tablespoons melted butter. Press firmly into the bottom and slightly up the sides. Bake 8–10 minutes.
Cool slightly.
Toast the pecans: Spread 1 to 1 1/4 cups pecans on a sheet pan. Toast at 325°F for 6–8 minutes until fragrant. Cool, then chop roughly.
Soften the caramel: Warm 1 cup caramel with 2 tablespoons heavy cream and a pinch of salt until pourable.
Spread a thin layer over the crust. Sprinkle half the pecans on top. Chill while you make the filling.
Mix the filling: Beat 24 ounces cream cheese with 3/4 cup sugar until smooth, about 2 minutes.
Add 3/4 cup sour cream and 2 teaspoons vanilla. Beat in 3 large eggs one at a time on low, just until combined. Don’t overmix.
Assemble: Pour filling into the crust.
Tap the pan gently to release bubbles.
Bake gently: Place the pan on a baking sheet. Bake at 325°F for 55–70 minutes, until edges are set and the center still jiggles slightly. Turn off the oven, crack the door, and let it sit 30 minutes.
Cool slowly: Remove and cool on a rack until just warm.
Run a thin knife around the edge. Chill at least 6 hours, preferably overnight.
Make the chocolate ganache: Heat 1/2 cup cream until steaming. Pour over 1 cup chocolate.
Let sit 2 minutes, then stir smooth.
Finish with toppings: Pour a layer of caramel over the chilled cheesecake, then drizzle the ganache. Sprinkle remaining pecans on top. Add a pinch of flaky sea salt if you like.
Slice cleanly: Warm a sharp knife under hot water, wipe dry, and cut.
Repeat between slices for neat edges.