Combine the butter, cream cheese, pumpkin puree, sweetened condensed milk, and pumpkin pie spice in a skillet over medium heat. Stir constantly until thickened and well-combined. Stir in the graham cracker crumbs and white chocolate chips.

Continue stirring until the mixture releases from the sides and bottom of the pan when stirred.

Pour the mixture onto a butter-greased baking sheet. Spread it into an even layer and refrigerate until firm, about 2 hours or overnight.

Rub some butter on your hands and roll the mixture into small balls.

Pour granulated sugar into a shallow bowl and roll each truffle ball in sugar until coated.

Using a toothpick, create ridges along the sides of each pumpkin truffle and top with chocolate chips.