Line the bottom of a 7-inch springform pan with parchment paper and lightly grease the sides. Combine graham cracker crumbs, sugar, and melted butter, then press the mixture firmly into the pan; chill the crust while preparing the filling.

Beat softened cream cheese and sugar until smooth, taking care not to overbeat and add excess air. Add the eggs one at a time, mixing only until each egg is blended.

Mix in pumpkin puree, vanilla, cinnamon, ginger, nutmeg, and salt. Pour the filling over the chilled crust and smooth the top.

Cover the springform pan tightly with aluminum foil to keep condensation from dripping onto the cheesecake. Pour about 1 inch of water into the slow-cooker insert, place a trivet or folded foil sling above the water, and set the pan on top.

Cover the slow cooker and cook on LOW for approximately 2 1/2 to 3 1/2 hours. The edges should be set while the center retains only a slight jiggle, and the lid should remain closed during cooking.

Turn off the slow cooker and let the cheesecake rest, covered, for about 30 minutes. Remove the pan, cool the cheesecake to room temperature, then refrigerate it for at least 4 hours, preferably overnight, before unmolding and serving.