This recipe is from Bon Appetit; the main thing I changed is the baking time (original is way too long).
Crust:
1 cup flour
3/4 cup brown sugar
1/4 t salt
1 stick cold unsalted butter, diced
1 cup pecan halves
2/3 cup oats
In a food processor, pulse the first four ingredients until coarse meal forms. Add the pecans and oats and pulse until incorporated. Butter a 9X9 metal baking pan. Press 3 1/2 cups of the crumbs into the pan and bake at 350ยบ for about 15 minutes until golden. Watch the crust carefully because it’s not good when over-baked. Keep the food processor out for the filling (you don’t need to wash it). On a rimmed baking sheet, bake the remaining crumbs for about 10-12 minutes, stirring once.
Filling:
8 oz. cream cheese softened
1 egg
3/4 cup pumpkin puree
1/2 cup sugar
1 t cinnamon
1/4 t ground ginger (or more if you like a lot)
Pour filling over crust and spread as evenly as possible; bake for 20 minutes (the sides should start to rise a bit).
While this is baking, make the topping:
1 cup sour cream
2 T sugar
1/4 t vanilla
Spread topping over the pumpkin filling and return to the oven for 5 more minutes. Top with the remaining crumbs and allow to cool completely. Refrigerate until cold (at least 2 hours before serving and it’s really better if you make it the day before you plan to eat it).