Moist, tender, crowned with rich, thick cream cheese icing — and gluten-free, to boot. Who could ask for anything more?
Preheat the oven to 350°F.
To make the cake: Grease and flour a large rimmed half-sheet pan, about 18" x 13"; or line the pan with greased parchment. Note: to make these bars in a 9" x 13" pan, see "tips," below left.
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.
To toast nuts, place them in a single layer on a baking sheet and bake in a 350°F oven for 8 to 10 minutes, just until you can start to smell them; let cool before using.
Want to use fresh pumpkin purée rather than canned? It’s simple to make your own; see how it’s done.
Be aware: Some of your baking ingredients can be a hidden source of gluten. Learn more at our blog post: For gluten-free baking, think beyond just flour. For additional information on King Arthur-produced products, read the complete details of our allergen program, including our contact-prevention practices.
