To prepare cake: Preheat oven to 350°F. Coat a 9-by-13-inch baking dish with cooking spray. Toast walnuts in a small baking pan in the oven until fragrant, 5 to 10 minutes. Let cool.
Drain pineapple in a sieve set over a bowl, pressing on the solids to thoroughly drain. Reserve the drained pineapple and 1/4 cup of the juice.
Whisk flour, baking soda, salt, cinnamon and nutmeg in a medium bowl. Whisk eggs, sugar, buttermilk, oil, vanilla and 1/4 cup of the reserved pineapple juice in a large bowl until blended. Stir in pineapple, carrots and 1/4 cup coconut. Add the dry ingredients and mix with a rubber spatula just until blended. Stir in the nuts. Scrape the batter into the prepared pan, spreading evenly.
Bake the cake until the top springs back when touched lightly and a toothpick inserted in the center comes out clean, 40 to 45 minutes. Let cool completely on a wire rack.
To prepare frosting and finish cake: Place coconut in a small baking pan and toast in the oven at 300°F, stirring several times, until light golden, 5 to 10 minutes.
Beat cream cheese, confectioners' sugar and vanilla in a mixing bowl with an electric mixer until smooth and creamy. (If desired, either add nutmeg to the frosting mixture, or sprinkle over cake when done). Spread the frosting over the cooled cake. Sprinkle with the toasted coconut.
TIPS Ingredient Notes: Whole-wheat pastry flour, lower in protein than regular whole-wheat flour, has less gluten-forming potential, making it a better choice for tender baked good. You can find it in the natural-foods, or bulk, section of large supermarkets & natural-foods stores. Store in the freezer.
Ingredient Notes: Large thin flakes of dried coconut called ''coconut chips'' make attractive garnishes. Find them in the produce section, or bulk-foods section of large supermarkets.
Tips: No buttermilk? You can use buttermilk powder prepared according to package directions. Or make ''sour milk'' by mixing 1 tablespoon of lemon juice or vinegar to 1 cup of milk.
To toast chopped walnuts and coconut chips, cook in a small dry skillet over medium-low heat, stirring constantly, until fragrant & lightly browned, 2-5 minutes.
NUTRITION INFORMATION:
Per serving: 342 calories; 17 g fat (5 g sat, 7 g mono); 56 mg cholesterol; 43 g carbohydrate; 6 g protein; 3 g fiber; 349 mg sodium; 150 mg potassium. Nutrition bonus: Vitamin A (40% daily value), Fiber (12% dv).
carbohydrate servings Exchanges: 2 1/2 other carbohydrate, 1/2 vegetable, 3 fat EatingWell.com
