In a large (2 qt.) baking dish, whisk 8 eggs, 1/2 cup cream of coconut and 1 tbsp. dark rum. Lay the 8 slices of bread in the egg mixture, turning often until the bread is soaked through, 2 to 3 minutes. In a griddle or large skillet, melt 1 tbsp. butter over medium heat. Add 4 soaked bread slices and cook until golden brown and cooked through, 2 to 3 minutes per side. Repeat with 1 more tbsp. butter and the remaining bread.
In a small bowl, toss 2 cups chopped pineapple with 2 tbsp. dark rum. Top the French toast with the pineapple mixture, toasted coconut flakes, a maraschino cherry and a drizzle of cream of coconut.