Sour Cream Pumpkin Bars

I got this recipe from a former co worker. It's a moist pumpkin treat that is a pleasant departure from the typical pumpkin seasonings. It is more like a cake than a bar.

Sour Cream Pumpkin Bars from Midwest Living
prep- 25 minutes bake- 25 minutes

1/2 cup butter, softened
1 1/3 cup sugar
1 1/2 teaspoons baking powder
1/4 teaspoon baking soda
1/4 teaspoon salt
2 eggs
1 cup canned pumpkin
1/2 cup dairy sour cream
1/4 cup milk
1 teaspoon vanilla
1 1/2 cups all purpose flour
1/2 cup whole wheat flour (I use AP flour if I don't have wheat flour)
1 cup chopped pecans or walnuts (I don't use them)
browned butter frosting (see recipe) (I use store bought whipped white frosting)
chopped pecans or walnuts (optional)

1. Grease a 15x10x1 inch baking pan; set aside. (I line mine with aluminum foil)

2. In a large mixing bowl, beat the butter with an electric mixer for 30 seconds. Beat in sugar, baking powder, baking soda and salt until combined. Add eggs, pumpkin, sour cream, milk and vanilla; beat until combined. Add all-purpose and whole wheat flours; beat until combined. Stir in 1 cup nuts.

3. Spread the mixture evenly into prepared baking pan. Bake in a 350 F oven about 25 minutes, or until a wooden toothpick inserted near the center comes out clean. (it took closer to 40 minutes in the oven in our old apartment). Cool in pan on wire rack.

4. Prepare the browned butter frosting as directed; spread over cooled bars. If you like, immediately sprinkle the frosted top with additional chopped pecans or walnuts. Cut into bars. Makes 48 bars.

Browned Butter Frosting- in a small saucepan, heat 1/2 cup butter over low heat until melted. Continue heating until the butter turns a light brown. Remove the saucepan from heat and transfer butter to a medium mixing bowl. Add 3 cups powdered sugar, 2 tablespoons milk and 1 teaspoon vanilla. Beat with an electric mixer until combined. Beat in additional milk, 1 teaspoon at a time, to make a spreadable frosting. Use immediately. Makes about 1 cup frosting.