Preheat oven to 275°F. Line 12-hole standard muffin pan with baking liners.
Food process toasted walnuts until fine. Add butter and sugar, process until combined. Divide mixture among baking cups; press firmly.
Beat cream cheese, pumpkin, sour cream, nutmeg, cinnamon, pumpkin pie spice, sugar and vanilla in a bowl with electric mixer until smooth. Beat in eggs, just until combined. Do not over beat. Pour mixture into baking cups. (Use low-fat sour cream and cream cheese- not fat free - because the taste and structure are compromised.)
Bake cheesecakes for 25-30 minutes or until the outside edges are firm and center is a little jiggly. Cool and refrigerate for at least 2 hours.
Remove from baking cup wrapper. Top with whipped cream and a dusting of cinnamon. Serve.