1 cup vegetable oil
1 cup brown sugar
1/2 cup granulated sugar
6 large eggs
1 cup pumpkin purée
1 teaspoon baking soda
1 teaspoon baking powder
1/2 teaspoon salt
1 tablespoon pumpkin pie spice, or 1 1/2 teaspoons cinnamon and 1/2 teaspoon each ginger, nutmeg, and cloves
3/4 teaspoon xanthan gum
2 cups King Arthur Gluten-Free 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 ounces cream cheese, softened
1/4 cup (4 tablespoons) unsalted butter, softened
2 tablespoons maple syrup
2 1/2 cups confectioners’ sugar, sifted
1/8 teaspoon salt
Preheat the oven to 350°F. Grease and flour a large rimmed half-sheet pan, about 18″ x 13″; or line the pan with greased parchment.
Beat the oil and the sugars together until well blended. Beat in the eggs, then the pumpkin purée.
Stir the baking soda, baking powder, salt, spice, and xanthan gum into the wet ingredients, then stir in the flour, beating gently to combine.
Stir in the nuts and raisins/ginger. Let the batter rest in the bowl for 15 minutes, then stir again to combine before pouring it into the pan.
Bake the bars for approximately 20 to 25 minutes, or until a cake tester or toothpick inserted into the middle of the cake comes out clean.
Cool the cake in the pan for 10 minutes, then turn it onto a rack to finish cooling; or leave it right in the pan, if you’ve lined the pan with parchment.
To make the frosting: Beat the cream cheese and butter together.
Beat in the maple syrup, then mix in the confectioners’ sugar and salt. Adjust the consistency of the frosting with additional maple syrup or confectioners’ sugar, if necessary; it should be nicely spreadable.
Frost the bars and sprinkle with the toasted walnuts. Once the frosting has set somewhat, cut into squares or rectangles.