1. Heat the oven to 325°F (160°C). Grease a 9-inch springform pan, line the bottom with parchment paper, and wrap the outside of the pan with a double layer of heavy-duty foil if using a water bath.

2. In a medium bowl, combine the graham cracker crumbs, light brown sugar, melted butter, and 1/4 teaspoon fine sea salt until evenly moistened and the mixture resembles damp sand.

3. Press the crust mixture firmly and evenly into the bottom of the prepared pan. Bake for 8–10 minutes, until lightly golden and fragrant, then set aside to cool slightly while you make the filling.

4. In a large mixing bowl, beat the softened cream cheese on medium speed until completely smooth and free of lumps.

5. Add the creamy peanut butter and granulated sugar and beat until the mixture is thick, fluffy, and well combined, scraping down the sides of the bowl as needed.

6. Mix in the 1/2 cup sour cream, 1 teaspoon of the vanilla extract, and 1/4 teaspoon fine sea salt for the filling on low speed until just blended.

7. Add the eggs one at a time, beating on low after each addition only until the yolk disappears and the batter is smooth; avoid over-mixing so you don’t incorporate too much air.

8. Pour the peanut butter filling over the baked crust and smooth the top with an offset spatula. Place the springform pan into a larger roasting pan and pour hot water into the outer pan until it reaches about halfway up the sides of the springform pan.

9. Bake for 55–65 minutes, or until the edges are set and the center still has a slight wobble when you gently shake the pan.

10. Turn off the oven, crack the door open a few inches, and let the cheesecake rest inside for about 1 hour to cool gradually.

11. Remove the cheesecake from the water bath, take off the foil, and run a thin knife around the edge of the pan to loosen the cheesecake. Let it cool completely at room temperature.

12. In a small bowl, whisk together the 1 cup sour cream for topping, remaining 1 teaspoon vanilla extract, powdered sugar, and milk or heavy cream until smooth and spreadable.

13. Spread the sour cream topping over the cooled cheesecake in an even layer, cover, and chill for at least 4 hours or overnight until fully set and cold.

14. Just before serving, gently warm the 1/4 cup creamy peanut butter until pourable and drizzle it over the top of the cheesecake in a criss-cross pattern.

15. Release the springform ring, slice the cheesecake with a sharp warm knife (wiping the blade between cuts), and serve.