1 lb (4 sticks) unsalted butter at room temperature
1 1/2 tsp pure coconut extract
Temper egg whites and sugar in a heatproof bowl over a pot of water on medium heat. I usually use the metal bowl from my stand mixer. You need just enough water to cover the bottom of the pot. Heat the mixture to 150°F. Make sure to stir constantly to avoid cooking the egg whites.
Remove the sugar and egg whites from heat. Using a wire whisk on your stand mixer, beat on low for two minutes. Increase to medium speed for five minutes. Increase speed to high and beat until stiff peaks form, about 3-5 more minutes.
Next, reduce speed to low and add butter 1 tbsp at a time, ensuring each addition is well mixed.
Add coconut extract and beat for another minute or two with the wire whisk.
Change your mixer attachment to the paddle attachment continue to beat on medium speed until well incorporated and glossy. It took several more minutes for me to achieve the consistency I was looking for.