Using your favorite pie crust recipe, make a crust to line a 9.5 inch deep dish pie plate. Set aside. Preheat oven to 350 F.
Beat the cream cheese in a medium bowl until it is fluffy. With the mixer on medium speed, beat in the granulated sugar, vanilla and 1 egg. Place in the fridge to chill for 30 minutes
In a separate bowl, stir together the pumpkin, half and half, 1/2 cup brown sugar, 2 eggs, pumpkin pie spice and salt.
Spread the cream cheese mixture on the bottom of the pie crust and carefully pour the pumpkin mixture on top. Bake in the preheated oven, loosely covered with foil, for 30 minutes. Remove foil and bake for another 30-40 minutes or until the center is just set.
Meanwhile, stir together the 3 tablespoons of brown sugar and flour. Cut in cold butter until crumbly. Stir in pecans. When the pie is just set, gently sprinkle on the pecan streusel and bake for another 10-15 minutes or until slightly brown. Remove from oven and cool on wire rack. Chill before serving.