The night before, combine the water, yeast, and sugar in a very large bowl (the batter will expand enormously). Allow it to stand for about 5 minutes, until the yeast dissolves and the mixture has started to foam, which tells you the yeast is active. Stir in the milk, butter, honey, vanilla, and salt. Add the flour and whisk until the batter is smooth. Cover the bowl with plastic wrap and allow it to sit overnight at a cool room temperature.
The next morning, heat a Belgian waffle iron according to the manufacturer's instructions and brush the top and bottom with melted butter. Beat the eggs together with the baking soda and whisk them into the batter until combined. Pour just enough of the batter onto the hot waffle iron to cover the grids (1/3 to 1/2 cup each, depending on your waffle maker), close, and cook for 5 to 6 minutes on medium heat, until the waffles are golden brown. Cut them apart with a small knife, if necessary, and remove them with a fork. Repeat the process until all the batter has been used. Serve the waffles hot with sliced bananas, toasted coconut, maple syrup, and creme fraiche and let everyone help themselves.