Pumpkin Cake Bars with Cream Cheese Frosting

INGREDIENTS

1 cup

vegetable oil

1 cup

brown sugar, packed

1/2 cup

granulated sugar

large eggs

1 cup

pumpkin purée

1 tsp

baking soda

1 tsp

baking powder

1/2 tsp

salt

1 tbsp

pumpkin pie spice, or 1 1/2 teaspoons cinnamon and 1/2 teaspoon each ginger, nutmeg, and cloves

2 cups

King Arthur Unbleached All-Purpose Flour or Gluten-Free Measure for Measure Flour

1/2 cup

toasted chopped walnuts

1 cup

golden raisins, or 1/2 cup golden raisins and 1/2 cup ginger mini-chips

8 oz

cream cheese, softened

1/4 cup

unsalted butter, softened

2 tbsp

maple syrup

2 1/2 cups

confectioners' sugar, sifted

1/8 tsp

salt

1 cup

toasted walnut pieces