Combine the butter, cream cheese, pumpkin, 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 until melted and smooth. Add a few drops of food coloring if desired.

Continue to stir until the mixture releases from the sides and bottoms of the pan.

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

Rub butter on your hands to prevent sticking and roll the chilled dough into small balls.

Roll the truffle balls in granulated sugar to coat.

Using a toothpick, make ridges along the sides of the truffles and top with chocolate chips to look like stems.

Serve immediately or refrigerate until ready to serve.