1. Combine yeast and warm water in a 1-cup glass measuring cup; let stand 5 minutes.
2. Meanwhile, combine flour and next 3 ingredients in a large bowl; make a well in center of mixture. Whisk together egg yolks, buttermilk, and next 2 ingredients. Whisk in yeast mixture; add to dry mixture, stirring just until moistened.
3. Beat egg whites at high speed with an electric mixer until stiff peaks form. Fold beaten egg white into batter. Cook in a preheated, oiled waffle iron until done.
4. Dollop whipped cream onto waffles. Top with Caramelized Bananas, and sprinkle with coconut and nuts.