Preheat oven to 350 degrees. Grease 8x8 baking pan.
Combine flour and brown sugar in bowl.
Cut in butter to make a crumb mixture. Stir in nuts.
Set aside 3/4 cup of crumb mixture for topping.
Press remaining crumb mixture in bottom of 8x8 pan.
Bake for 15 minutes. Cool slightly.
Combine cream cheese, sugar, pumpkin, eggs, cinnamon, and vanilla in large mixing bowl. Blend until smooth. Pour over baked crust.
Sprinkle with reserved topping.
Bake an additional 30 minutes. Cool before cutting bars.