Coconut Rum Butter cream Frosting
1 ¼ cups granulated sugar, divided
6 tablespoons water
6 large egg whites
¾ teaspoon cream of tartar
5 sticks unsalted butter, at room temperature
1/3 cup coconut cream
2 tablespoons light rum
Combine 1 cup sugar and the water in a medium-size heavy saucepan.
Heat over medium high, stirring constantly until sugar dissolves.
Wash down sides of pan with a brush dipped in water.
Place candy thermometer in the sugar syrup, clip to side of saucepan.
While sugar syrup is cooking, in a mixing bowl, beat egg whites until frothy. Add cream of tartar and beat until soft peaks. Add remaining ¼ cup sugar and beat until stiff peaks; stop mixer and check sugar syrup.
When sugar syrup reaches firm ball stage (250 degrees), remove from heat and add in increments to egg whites, stopping machine while adding the syrup and beating for 5 seconds between each addition.
Once all sugar syrup has been added, beat on high speed slightly cooled, about 2 to 5 minutes.
Beat in the butter at medium speed, 1 or 2 tablespoons at a time.
Once all butter has been incorporated, turn mixer to low speed and slowly drizzle in coconut cream and rum.
Increase to high speed and beat until completely incorporated and buttercream is light and fluffy.