1. Heat oven to 325°F (163°C). Line the base of a 9-inch springform with parchment and lightly grease the sides. Wrap the outside of the pan in 2 layers of heavy-duty foil for a water bath. Place a large roasting pan on the center rack.

2. Make the crust: Stir graham crumbs, brown sugar, melted butter, and salt to combine. Press firmly into the pan. Bake 8–10 minutes until lightly golden. Cool while you prepare apples.

3. Cook apples: In a skillet over medium heat, melt butter. Add apples, brown sugar, cinnamon, nutmeg, lemon juice, and salt. Cook 5–7 minutes until tender with glossy juices. If very juicy, sprinkle in cornstarch and cook 30 seconds. Cool to room temp.

4. Mix filling: Beat cream cheese until completely smooth (1–2 min). Add sugar; beat 1 min. Mix in sour cream, vanilla, and salt. Add eggs one at a time on low, mixing just to combine; scrape bowl often.

5. Assemble: Pour half the batter over the crust. Scatter half the apples evenly. Add remaining batter; smooth. Spoon remaining apples on top and lightly press so they sit just in the surface.

6. Make streusel: Combine oats, flour, brown sugar, cinnamon, and salt. Cut in cold butter until sandy clumps form. Sprinkle evenly over the top.

7. Bake (water bath): Set the foil-wrapped pan in the roasting pan. Pour hot water into the roasting pan to reach halfway up the springform. Bake 65–80 minutes, until edges are set and the center has a slight wobble. Tent with foil if topping browns too fast.

8. Cool & chill: Turn off oven, crack the door, and let rest 30 minutes. Remove from bath; cool to room temp. Run a thin knife around the edge. Chill at least 6 hours, preferably overnight.

9. Finish & serve: Release the ring. Slice with a hot, dry knife (wipe between cuts). Drizzle with warm caramel and add whipped cream and toasted pecans, if desired.