Cookie Crust:

Grease an 8-inch square baking pan. Preheat oven to 350.

In a bowl, combine  flour, rolled oats,  chopped pecans,  brown sugar,  butter, 1teaspoon vanilla and  ground cinnamon. Mix well and press the mixture into the prepared baking pan.

Bake crust for 10 minutes and then let cool completely.

Filling:

In a bowl ,combine the pureed pumpkin, eggs, milk, brown sugar, nutmeg, cinnamon and ginger. Mix well.

Pour the mixture over the cooled cookie base; Bake for about 40 minutes, or until set. Transfer to wire rack to cool completely.

Topping: 

Beat cream cheese at medium speed until creamy.

Add the confectioner's sugar and vanilla to the cream cheese and beat until smooth.

Spread the topping over the cooled filling and cut into 12 bars and decorate with pecan halves.