Line a baking sheet with parchment paper and set it aside.
In a large mixing bowl, beat the softened cream cheese, pumpkin puree, powdered sugar, vanilla extract, pumpkin pie spice, cinnamon, and salt until smooth and creamy. Scrape down the sides of the bowl as needed.
Add the graham cracker crumbs and mix on low speed until fully combined.
Cover the bowl tightly and refrigerate the filling for at least 2 hours, or until firm enough to scoop and roll.
Use a small cookie scoop or tablespoon to portion the chilled filling into 24 pieces. Roll each piece gently between clean palms to form smooth balls. Place the truffles on the prepared baking sheet.
Freeze the rolled truffles for 20 to 30 minutes, until firm.
Melt the white chocolate wafers or candy coating in a microwave-safe bowl in 20-second intervals, stirring after each interval until smooth. If using white chocolate chips, stir in the coconut oil or shortening to help the chocolate melt smoothly.
Use a fork to dip one chilled truffle into the melted white chocolate. Lift it out and tap the fork gently on the side of the bowl to remove excess coating.
Return the coated truffle to the parchment-lined baking sheet. Immediately add any desired decorations before the coating sets.
Repeat with the remaining truffles. Refrigerate for 20 to 30 minutes, until the coating is firm.
Serve chilled or let the truffles sit at room temperature for 10 to 15 minutes before serving for a softer center.