Created by Engrossed on January 21, 2012
Step 1: Preheat oven to 350F. Grease a 15x10x1-inch or 13x9x2-inch baking pan; set aside.
Step 2: In a large mixing bowl whisk together the flour, baking powder, orange zest, baking soda, and salt. Set aside.
Step 3: In a medium bowl combine eggs and brown sugar. Stir in pumpkin, oil, milk, and vanilla. Then stir in carrots and chopped walnuts.
Step 4: Add egg mixture to flour mixture, stirring with a wooden spoon until combined.
Step 5: Spread batter into prepared baking pan. Bake for 20 to 25 minutes in a 15x10x1 pan or 28 to 33 minutes in a 13x9x2 baking pan, or until tests done. Cool in pan on a wire rack.
Step 6: For Orange Icing: In a mixing bowl combine powdered sugar and enough of the orange liqueur, orange juice or orange concentrate to make an icing that is easy to drizzle.
Step 7: Spread cooled cake with orange icing; cut into triangles or bars. If desired, garnish each bar with a walnut half.
Step 8: Store in an airtight container in the refrigerator for up to 3 days. Make-Ahead Tip: Bake bars as directed; cool completely. Do not drizzle with icing. Place cut bars in a freezer container and freeze for up to 1 month. Before serving, thaw for 15 minutes. Prepare Orange Icing and drizzle as directed.