Preheat your oven to 325°F (160°C) and grease a 9-inch springform pan lightly with butter or non-stick cooking spray.

In a mixing bowl, combine the graham cracker crumbs, granulated sugar, and melted butter. Stir until the mixture resembles wet sand, then pour it into the prepared springform pan.

Firmly press the crumb mixture into the bottom of the pan and bake for 10 minutes. Let it cool completely.

In a large mixing bowl, beat the softened cream cheese with an electric mixer until creamy and smooth. Gradually add granulated sugar and mix until combined.

Stir in the pumpkin puree until fully blended, then add the eggs one at a time, mixing gently after each addition.

Mix in the vanilla extract, cinnamon, nutmeg, ginger, and salt until just combined.

Carefully pour the cheesecake filling over the cooled crust, smoothing the top with a spatula.

In a separate bowl, mix together the flour, rolled oats, brown sugar, and softened butter until crumbly.

Sprinkle the streusel topping evenly over the cheesecake filling.

Bake in the preheated oven for 40-45 minutes, until the edges are set and the center is slightly jiggly.

Let the cheesecake cool for 15-20 minutes, then refrigerate for at least 3 hours, or preferably overnight.