Chocolate Chip- Pumpkin Spice Bars

I got this recipe from
http://www.recipegirl.com/

BATTER:
1 ¾ cups pure pumpkin puree
1 cup canola oil
4 large eggs
1½ cups granulated sugar
½ cup brown sugar
1 cup all-purpose flour
1 cup whole- wheat pastry flour
2 tsp baking powder
2 tsp ground cinnamon
1 tsp baking soda
½ tsp salt
½ tsp ground ginger
¼ tsp ground cloves
¾ cup mini- chocolate chips

FROSTING:
8 ounces cream cheese, softened
4 Tbs butter, softened
2 tsp milk
1 tsp pure vanilla extract
4 cups powdered sugar, sifted
½ cup mini- chocolate chips (for topping)

1. Prepare batter: Preheat oven to 350°F. Spray 10×15-inch baking pan with nonstick spray.
2. In a large bowl, whisk together pumpkin, oil, eggs and sugars until combined.
3. In a separate bowl, whisk together flours, baking powder, cinnamon, baking soda, salt, ginger and cloves. Toss in mini chocolate chips and stir to combine. Add dry ingredients to the wet and stir until moistened.
4. Pour batter into prepared pan coated with nonstick spray. Bake until the center springs back when lightly pressed in the center- about 25 to 30 minutes. Remove and place on wire rack to cool completely.
5. Prepare frosting: In a large mixing bowl, beat together cream cheese, butter, milk and vanilla. Slowly add the powdered sugar, 1 cup at a time, and mix until smooth. Frost bars and sprinkle with additional mini chocolate chips.
Yield: About 42 bars
Recipe Source: Adapted from Betty Crocker"