Pineapple and coconut are definitely a marriage made in Heaven. This moist and pudding-like cake is in a very fresh tasting and tropical type dessert. The fact that it is served cold, makes it extremely refreshing. I used a Pineapple Supreme Cake Mix by Duncan Hines. It is part of a Signature Series of Cake Mixes. Feel free to use your own scratch recipe, but I found the boxed cake yielded very tasty results. For beginners, the custard is not too terribly difficult, but you must make sure that you whisk very fast and constantly so the egg yolks do not scramble. Other than that, "Piece O' Cake"
At least 2 hours ahead, or the day before, make the custard filling. Make sure it is chilled well. You can speed this up by chilling in a bowl over ice water.
To make the custard, place all the custard ingredients, except the coconut and the almond extract in a medium heavy bottomed sauce pan. Whisk to blend well. Place pan over med/lo heat and whisk constantly until it starts to thicken. At this point, do an on burner off burner technique, whisking constantly for about 2 minutes more until well thickened. Do not boil, as the egg yolk will scramble.
Immediately transfer the thickened custard to a bowl and stir in the almond extract and coconut. Place plastic wrap directly on top of the custard to prevent a skin from forming. Place in fridge to thoroughly chill.
Prepare the cake as directed on the box in (2) 8 inch pans. Cool on rack 10-15 minutes, then invert on to rack to cool completely. While warm, brush the layers with the 4 tsp white rum.
When cake is cooled, place 1 layer on a cake plate. Spread 1/2 of the custard on top of layer. Chill layer in fridge for 15 minutes or so to set. Remove from fridge and place the second layer on top. Spread with the remaining custard. Place in fridge while you prepare the frosting.
To make the frosting, place all of the frosting ingredients in a medium bowl and beat with a wooden spoon until quite smooth. This is best done by hand, as a mixer tends to put too much air in the buttercream.
Take the cake out of the fridge and frost the sides of the cake. You will need the use a little at a time while you work your way around the sides of the cake.
Scatter the coconut flakes on top of the cake.
Place cake back in the fridge and chill at least one hour before serving cold directly from the fridge. Serves 10.