In a large mixing bowl with whisk attachment, beat the egg whites until foamy on a low speed.
Add cream of tartar and salt and continue to beat, gradually increasing the speed to high.
When the egg whites get whiter, add remaining ¾ cup of sugar one tablespoon at a time.
Add pure vanilla extract and continue to beat on high speed until hard peaks form.
Transfer the whipped egg whites into a large bowl.
Add flour/sugar mixture and carefully mix everything together. Be careful not to deflate the batter too much.
Now transfer the batter to ungreased angel food cake pan. Even out the surface. Run a butter knife through the batter to remove any air bubbles.
Bake for about 40-45 minutes. It’s ready if the inserted wooden stick comes out clean.
Cool the cake completely in the pan upside down for 90-120 minutes. This will make sure the cake stays soft and fluffy while cooling.
For pineapple whipped cream filling:
Whisk the heavy cream with sugar until hard peaks form. (Adjust the sugar to your taste.)
Drain the pineapple, reserving the juice for later. Carefully fold in the crushed pineapple into the whipped cream. Refrigerate until ready to use.
To make cream cheese frosting:
In a mixing bowl with paddle attachment beat cream cheese and butter on medium high speed.
Add powdered sugar, pineapple juice and coconut extract. Continue to beat until nice and smooth. Refrigerate until ready to use.
To toast the coconut flakes:
Spread the coconut flakes evenly on a cookie sheet. Bake it for 5-8 minutes at 350°F (177°C), or until nice and golden, stirring every few minutes.
To assemble the cake:
Cut the cooled cake horizontally and remove the top layer. Using a small knife, cut out a tunnel in the center of the bottom layer.
Evenly soak the cake with a little bit of reserved pineapple juice (mix with rum, if desired).
Fill the tunnel with pineapple whipped cream. Place the top layer and frost with cream cheese frosting. Then cover with toasted coconut flakes.
If desired, pipe cream cheese frosting on the top and garnish with maraschino cherries.
Note 1: To make homemade cake flour, measure out 1 cup of all-purpose flour, remove 2 tablespoons of it and add 2 tablespoons of cornstarch. Sift and you have a DIY cake flour!Note 2: Caster sugar is basically super fine granulated sugar. If you don’t have it, you may pulse regular granulated sugar in a food processor, or blender, until nice and fine. Fine sugar dissolves quicker in the meringue, creating nice and stable meringue. Powdered sugar (or confectioner’s sugar) won’t work here.Note 3: Fresh egg whites are best for making Angel food cake. And here’re 6 ideas for leftover egg yolks.Note 4: Cream of tartar is an acid that stabilizes egg whites, making stronger and more stable meringue. While it’s highly recommended, it’s not crucial ingredient.Note 5: Make sure to use plain brick-style cream cheese for nice and sturdy frosting.Storing Tip: Store leftover cake, covered, in the fridge for up to 5 days.