Preheat oven to 325°F (160°C) and grease a 9-inch springform pan. Line the bottom with parchment paper.
In a bowl, mix graham cracker crumbs, melted butter, sugar, and salt until it resembles damp sand. Press firmly into the pan and bake 10 minutes. Let cool.
Beat cream cheese and brown sugar until smooth. Add eggs one at a time, mixing after each, then stir in vanilla. Gradually add heavy cream and melted butterscotch chips until the batter is silky.
Pour cheesecake batter over the cooled crust and smooth the top.
Combine flour, brown sugar, and salt in a bowl. Cut in cold cubed butter with fingers until coarse crumbs form. Sprinkle evenly over the cheesecake.
Bake 50–60 minutes until the center is set and topping is golden. Let cool in the oven with the door slightly open for 1 hour.
Cool to room temperature, then refrigerate at least 4 hours or overnight. Remove from pan, slice, and serve.