In the bowl of a standing mixer fitted with a whip attachment, cream the butter. Then add the cream cheese and continue mixing. Add the sugar and beat until fluffy. Beat in the eggs, vanilla, and flour. Set aside.
To make the pumpkin layer, in a mixer fitted with the whisk attachment (or using a hand mixer), mix the pumpkin puree and eggs until well blended. Add the sugars and mix. Add the remaining ingredients and mix until blended.
Line a 9 by 13-rectangular pan with parchment so that the parchment covers the bottom, sides and hangs over the edges of the pan. The over hanging parchment will be the 'handles' that will help you remove the bars once cooked and cooled. Spread the cream cheese layer evenly in the parchment-lined pan and bake for 25 minutes. It should be 3/4 to 1-inch thick. Pour the pumpkin layer over the cream cheese layer and continue cooking another 30 minutes. Cool completely in the pan to room temperature, then refrigerate. Cut into bars. Serve cold.
It's like having pumpkin pie with whipped cream only the "cream" is on the bottom