To create a dairy-free version, replace the egg and egg white with 2 tablespoons ground flaxseeds and 1/3 cup water, blending into a thick mixture as directed in the Middle Eastern Lentil-Bulgur Loaf, and substitute 7/8 cup soy milk mixed with 2 tablespoons fresh lemon juice for the buttermilk.You can bake the bars weeks in advance. Cool, wrap airtight and freeze up to 2 months. Top and cut bars the day of the party. Leave them in the baking pan for transport or transfer to a large airtight food storage container.
1. Preheat oven to 350°F. Coat 13 x 9-inch baking pan with cooking spray.
2. In medium bowl, whisk together both flours, cinnamon, baking powder, baking soda, salt and nutmeg. Stir in dates.
3. In another medium bowl, whisk together buttermilk, pumpkin puree, oil and vanilla.
4. In large bowl, combine egg, egg white and brown sugar. Beat with an electric mixer at high speed until thickened and fluffy, 3 to 5 minutes. With rubber spatula, stir in dry ingredients alternately with liquid ingredients, making 3 additions of dry and 2 additions of liquid. Scrape batter into prepared baking pan, spreading evenly.
5. Bake until top springs back when lightly touched in center, 25 to 30 minutes. Transfer to wire rack and let cool completely in pan. Leave oven on.
6. Meanwhile, make topping: Spread nuts in small baking pan and bake until fragrant, 5 to 10 minutes. Let cool; chop coarsely if necessary.
7. In medium bowl, whisk together confectioners’ sugar and vanilla. Gradually whisk in enough maple syrup to make coating consistency. Spread over cooled cake and immediately sprinkle with nuts. Let stand until topping has set, about 30 minutes. Cut into small bars.