To prepare cake: Preheat oven to 350 degrees F. Coat two 9-inch cake pans with cooking spray.

Sift cake flour, whole-wheat flour, baking powder and 1/4 teaspoon salt into a medium bowl. Beat 3/4 cup sugar, honey, oil and melted butter in a large bowl with an electric mixer on medium speed until well blended. Whisk buttermilk (or milk), rum and coconut extract in a small bowl. With the mixer on low speed, alternately mix the dry ingredients and the wet ingredients into the sugar mixture, starting and ending with dry ingredients and scraping the sides of the bowl as needed, until just combined.

Clean and dry the beaters. Beat 3 egg whites in a medium bowl with the electric mixer on medium-high until soft peaks form. Gently fold the whites into the batter in two additions until just combined. Divide the batter between the prepared pans, spreading to the edges.

Bake the cake until a toothpick inserted in the center comes out clean, 26 to 30 minutes. Cool in the pans on a wire rack for 10 minutes. Turn out and let cool to room temperature, about 1 hour.

To prepare curd: Whisk 2 egg yolks, pineapple juice, 1/4 cup sugar and cornstarch in a small saucepan. Cook over medium-low heat, whisking constantly, until thick and beginning to bubble, 3 to 5 minutes. Let cool completely.

To prepare frosting & assemble cake: Beat cream cheese, confectioners' sugar, extract (or rum) and a pinch of salt in a medium bowl with an electric mixer until smooth and creamy.

Place one cake layer, top-side down, on a cake stand or plate. Spread evenly with the pineapple curd, stopping just short of the edge. Scatter 1/2 cup diced pineapple over the curd. Place the remaining layer, top-side up, on top. Spread the frosting over the top and sides. Decorate the top with the remaining 1 cup pineapple and toasted coconut.

Note: White whole-wheat flour, made from a special variety of white wheat, is light in color and flavor but has the same nutritional properties as regular whole wheat. Whole-wheat pastry flour can sometimes be used as a substitute. Find it in the baking section of the supermarket or online at King Arthur Flour, (800) 827-6836, bakerscatalogue.com.

Tip: Toast coconut in a small dry skillet over medium-low heat until golden, stirring often, about 5 minutes.

MAKE AHEAD TIP: Equipment: Two 9-inch round cake pans