What sets these waffles apart from the “Brussels” style of Belgian waffle you might be used to is that they're made from a yeast dough dotted with pieces of pearlized sugar (or crushed sugar cubes!) They caramelize when they're pressed on the iron, yielding a waffle with a sweeter taste and a lovely crunch to it. If you don't have pearl sugar, crushing sugar cubes until they are broken down (coarse, not fine) is a great option as well.
1. Place the sparkling water in the bowl of a mixer fitted with the hook attachment and add the yeast. Add the eggs and sugar and mix for a moment to blend. Add the flour and salt and start the mixer on low speed, pouring in the melted butter while mixing. Once the ingredients are blended, increase the speed by one and knead the dough until it becomes elastic and smooth, about 5 minutes. Cover the mixing bowl with plastic wrap and set aside for an hour to rise (it will double in size).
2. Turn the dough out onto a clean work surface (because of the butter in the dough, it’s unlikely you’ll need to dust your work area with flour.) Press the dough out into a rough rectangle and sprinkle the pearl sugar over top. Roll up the dough and knead and twist it to work the sugar into the dough. Shape the dough into a log and cut it into 12 equal pieces. Shape each into a ball (it does not have to be precisely shaped) and set aside.
3. Preheat your waffle iron according to manufacturer’s instructions. Place a piece of dough into the centre of the iron, close the iron and flip. Cook the waffle for about 3 minutes, until a rich golden brown (the pockets of sugar will caramelize). Remove the waffles and repeat with the remaining pieces. The waffles can be served warm on their own or with caramel sauce, chocolate sauce or crème fraiche.
The waffles are best enjoyed the day they are made, but the dough can be made (without the pearl sugar added) the night before and kept chilled.