1. Preheat oven to 325 degrees F and line a muffin tin with paper cupcake liners. Spray with cooking spray.
2. Melt butter in a microwave-safe bowl and add to bowl of graham cracker crumbs. Mix until completely combined.
3. Scoop 1 ½ tbsp of graham cracker crumb mixture into each lined muffin tin section. Pack down.
4. Bake graham cracker crusts for 5 minutes.
5. In a large bowl, use an electric mixer to beat cream cheese, pumpkin puree, sour cream, sugar and egg. Mix on high speed until smooth.