These cake-type bars are moist and delicious, similar to carrot cake but with a fall flavor. The rich cream cheese frosting will also remind you of carrot cake — which isn't a bad thing! Do toast the walnuts before using them; toasting brings out their nutty essence.
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.
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, and spice into the wet ingredients, then stir in the flour, beating gently to combine.
Stir in the nuts and raisins/ginger.
Pour the batter into the prepared pan, and bake 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.
Want to make this recipe in a 9" x 13" pan? Change the amounts of ingredients as follows: 2/3 cup vegetable oil, 2/3 cup brown sugar, 1/3 cup granulated sugar, 3 large eggs, 2/3 cup pumpkin purée, 3/4 teaspoon baking soda, 3/4 teaspoon baking powder, 3/8 teaspoon salt, 2 teaspoons pumpkin pie spice, 1 1/3 cups (160g) King Arthur Unbleached All-Purpose Flour, 1/3 cup chopped toasted walnuts, 2/3 cup golden raisins/ginger mini chips. Bake as directed in the original recipe. For the frosting, reduce ingredients as follows: 4 ounces cream cheese, 2 tablespoons softened butter, 1 tablespoon maple syrup, 1 1/4 cups confectioners' sugar, pinch of salt, 1/2 cup diced toasted walnuts.
Want to make these gluten-free? For great results, substitute King Arthur Gluten-Free Measure for Measure Flour for the all-purpose flour in this recipe. Be sure to bake thoroughly; gluten-free baked goods often need a bit more time in the oven.
