Step 1

Heat oven to 350° F. Butter and flour 2 8-inch cake pans.

Step 2

In a large mixing bowl with a hand mixer or stand mixer, cream butter and sugar until smooth, about 5 minutes. Add egg yolks and blend until mixture appears light and fluffy, about 5 minutes. Add pineapple and its juices with the vanilla, and blend until combined. Sift flour and baking powder into the bowl with the butter and pineapple mixture.

Step 3

Add the milk, 1/2 cup coconut and the egg whites to a separate bowl. Mix on low speed just until everything is combined. Then, fold mixture into pineapple mixture.

Step 4

Divide the batter equally into the prepared pans. Sprinkle remaining coconut on top of each cake. Bake until golden brown and the cake springs back to the touch, about 35 minutes.

Step 5

Set pans on wire rack and allow to cool for 10 to 15 minutes. When cool to touch, flip cake out of pans onto rack and allow to cool completely.

Step 6

In small saucepan, mix 2 cups sugar with the milk over medium-low heat. Cook slowly, stirring regularly, until the sugar is dissolved and the milk is just coming to a boil.

Step 7

Meanwhile, in large saucepan with high sides, caramelize 1 cup sugar over medium-low heat. Stir the sugar constantly with a wooden spoon until it has melted and become a golden brown color. It will appear lumpy, but just keep stirring. As soon as it is amber, slowly add the hot milk into the large saucepan. Be careful since the mixture will bubble up very high.

Step 8

Stir the sugar and milk mixture constantly. Cook until about 230° F and the bubbles in the syrup have slowed down.

Step 9

Remove the sugar from the heat and immediately pour into the bowl of a stand mixer. Add the butter and vanilla extract. Let stand for 5 minutes without stirring, then beat until the frosting reaches a spreadable consistency, until it is cooled entirely, about 15 minutes. It will be gooey and sticky.

Step 10

Place one cake round on plate or cake stand. Spoon frosting onto cake top and smear across top. Add second cake round and coat the entire cake.