How to Make It
Beat coconut cream in a medium bowl with an electric mixer on high speed until thickened and very soft peaks form, 1 to 2 minutes. Beat heavy cream in a separate bowl on high speed until thickened and medium peaks form, about 2 minutes. Gently fold coconut cream into whipped cream; fold in coconut sugar.
Slice off top and bottom of citrus fruits. Stand them on end and use a knife to remove peel in strips from top to bottom. Holding fruit over a bowl to catch juices, section grapefruit and oranges between membranes, discarding membranes; reserve 1/2 cup citrus juices. Combine citrus sections and pineapple in a medium bowl; drain.
Place 2 cups of the angel food cake pieces on the bottom of a 12-cup trifle bowl; drizzle cake pieces with 2 tablespoons of the reserved citrus juice. Top with 1 1/2 cups of the fruit mixture, 3 tablespoons of the coconut flakes, and 2/3 cup of the cream mixture. Repeat layers until bowl is full (about 5 layers, depending on depth and height of bowl). Serve immediately or chill until ready to serve, up to 2 hours.