With orange cream cheese frosting.
A conceptually similar (but structurally different, using shortening) recipe for orange-frosted pumpkin bars appeared in the September 18, 1969 edition of the Statesville (North Carolina) Record and Landmark:
Pumpkin Nut Bars
1/2 cup shortening
Combine all ingredients except nuts in large mixer bowl. Beat for two minutes with electric mixer at medium speed. Fold in nuts. (Black walnuts are great for these.) Spread in 13 by nine by two inch pan. Bake at 350 degrees 20 to 25 minutes. Spread when cool with orange frosting.
Blend until smooth two tablespoons shortening, one and one-half cups powdered sugar, one tablespoon grated orange peel and two tablespoons fresh orange juice. Makes about one cupful.
From a box sold in Martinez, California.
Pumpkin Bars or Persimmon Bars
1/2 c. vegetable oil
2 c. sugar
1 (16 oz.) can pumpkin or persimmon pulp
2 [c.] flour
2 t. ground cinnamon
3/4 t. ground ginger
3/4 t. ground cloves
3/4 t. ground nutmeg
3/4 t. salt
2 t. baking powder
1 t. baking soda
In large bowl of electric mixer, beat egg lightly. Beat in oil, sugar and pumpkin.
In another bowl, sift together flour, cinnamon, ginger, cloves, nutmeg, salt, baking powder, and baking soda. Gradually add to pumpkin mixture.
Pour batter into greased and flour dusted 10×15″ rimmed baking pan. Bake 25 minutes, 350 degrees.
Orange Cream Cheese Frosting
1 (3 oz.) package cream cheese, softened
2 T. butter or margarine, softened
1-1/2 t. milk
1/2 t. vanilla
3/4 t. grated orange peel
2 c. powdered sugar