Step 1: Activate yeast in lukewarm milk with 1 tsp sugar, let sit 10 minutes until foamy.
Step 2: In large bowl, mix flour, salt, and remaining sugar. Make well in center.
Step 3: Add yeast mixture, eggs, and vanilla to flour. Mix until shaggy dough forms.
Step 4: Add softened butter in 4 additions, mixing thoroughly between each until smooth.
Step 5: Knead dough 8-10 minutes until elastic and slightly sticky. Place in greased bowl.
Step 6: Cover and let rise 1-2 hours until doubled in warm place.
Step 7: Gently fold pearl sugar into risen dough until evenly distributed.
Step 8: Divide dough into 8 equal portions, shape into balls, rest 15 minutes.
Step 9: Preheat Belgian waffle iron to medium-high. Cook each ball 3-4 minutes until deeply golden.
Step 10: Let waffles cool 2 minutes on rack before serving warm.