Add the warm milk to the bowl of a stand mixer fitted with the dough hook. Add 1 tsp of the granulated sugar. Add the yeast. Lightly mix. Let sit for 10 minutes so that the yeast can bubble.
Add the eggs and melted butter and whisk to combine. Add 2 cups of flour. Mix for 30 seconds or so, or until the flour is wet. Add the sugar, salt, vanilla and the remaining 2 cups of flour and mix for 4 minutes. The dough should pull away from the sides of the bowl.
Cover the bowl with plastic wrap and let rise for 1-2 hours, or until doubled in size.
Deflate the dough by pressing down on it in the center. At this point you can wrap the dough in plastic wrap and refrigerate overnight if you want to make the dough in advance. You would then continue in the morning by removing the dough from the fridge and letting it sit at room temperature for 30-40 minutes or until it's close to room temperature.However, you don't have to let the dough rest overnight you can continue straight through if desired.
Transfer the dough to a clean counter. Flatten the dough slightly and place the pearl sugar in the center. Knead the sugar into the dough until evenly distributed.
Divide the dough into 12 equal portions of dough.
Cover the dough balls and let them rest for 10 minutes. Heat your waffle iron.
Place dough balls in the center of your waffle iron. Cook for about 3-4 minutes or until they are golden brown and the sugar has melted. Keep an eye on the waffles as each waffle iron is different.
Serve warm. Top with Biscoff, Nutella, fresh whipped cream and berries.
Notes
If you're not serving them right away, you can keep the waffles warm in a 200°F oven. If you can control the temperature of your waffle iron, start low. Pearl sugar can burn easily. You don't want to heat the iron above 350ºF.