Yield: 1 layer cake, 12 servings.
Per slice: 370 calories, 17.5 g total fat (7.5 g saturated fat), 10 g protein, 46 g carbohydrate, 4 g fibre, 83 mg cholesterol, 549 mg sodium.
In a medium bowl, beat together cream cheese and butter until well blended. Gradually add icing sugar and beat until well blended. Add orange juice concentrate and orange zest and mix well. Cover and refrigerate until ready to use.
To make cake, preheat oven to 350ºF. Lightly grease two 9-inch round cake pans. Cut circles of parchment paper to fit bottoms. Lightly grease paper. Set pans aside.
In a medium bowl, combine flour, ground flax, baking soda, baking powder, cinnamon, nutmeg, ginger and salt. Set aside.
Using low speed of electric mixer, beat together pumpkin, brown sugar, buttermilk, oil, eggs, and vanilla until well blended. Add dry ingredients to wet ingredients and mix using a wooden spoon just until dry ingredients are moistened. Do not use a mixer for this step. Gently fold in carrots, walnuts, and coconut.
Divide batter evenly among baking pans. Bake on middle oven rack for about 30 minutes, or until a toothpick inserted in centre of cakes comes out clean. Cool cakes in pans on a wire rack for 10 minutes. Remove cakes from pans and cool completely before frosting.
To frost cake, place one cake layer on a pretty plate. Spread 1 cup frosting over top. Top with second cake layer. Frost top and sides of cake with remaining frosting. If desired, press finely chopped walnuts into sides of cake. Keep cake refrigerated.