Caramel Swirl Cheesecake

Position a rack in the center of the oven and preheat to 350 degrees F. Place the walnuts in a cake or pie pan and toast for 12 minutes, stirring the pan after 6 minutes. Remove the pan from the oven and cool. Reduce the oven temperature to 300 degrees F. Spray the inside of the springform pan with nonstick baking spray. Wrap heavy-duty aluminum foil tightly around the bottom of the pan to prevent water from seeping in as it bakes in a water bath. Pulse the walnuts and brown sugar in the work bowl of a food processor fitted with the steel blade until the walnuts are finely ground, about 1 minute. Pour the butter through the feed tube and pulse until the mixture begins to hold together in moist clumps. Transfer the mixture to the springform pan and press the crust evenly onto the bottom.