Make the waffles: Warm the milk and sugar in a medium saucepan over medium heat, whisking occasionally, until a thermometer registers 105 degrees F; remove from the heat. Sprinkle the yeast over the top and whisk to dissolve; let stand until foamy, about 5 minutes.
Meanwhile, whisk the flour, nutmeg, salt and cloves in a large bowl; make a well in the center. Whisk the melted butter into the milk mixture, then pour into the well in the flour and whisk until almost smooth (a few small lumps are OK). Cover with plastic wrap and let stand at room temperature until the batter has doubled in size and is bubbly, about 1 1/2 hours.
Preheat the oven to 200 degrees F. Put a wire rack on a baking sheet. Preheat a waffle iron according to the manufacturer?s directions, then lightly brush with melted butter. Stir the eggs and egg yolk and rum into the batter. (The batter will deflate.) Working in batches, fill the waffle iron about three-quarters full with batter and cook until golden and crisp, 3 to 7 minutes. Transfer the waffles to the rack and keep warm in the oven between batches.
Make the topping: Combine the dulce de leche, rum and nutmeg in a small bowl; stir until smooth. Gradually add 2 to 3 teaspoons warm water until
thin enough to drizzle. Top the waffles with ice cream and drizzle with the dulce de leche.
Photograph by Levi Brown