In a large mixing bowl, combine warm water, active dry yeast, and sugar. Let sit for 5-10 minutes until frothy.

Gradually add all-purpose flour and salt, mixing until a dough forms. Knead on a floured surface for 5 minutes until smooth.

Place dough in a greased bowl, cover, and let rise in a warm place for about 45 minutes, until doubled in size.

Punch down the dough and divide into 8 pieces. Roll each into a 24-inch rope, shape into a pretzel, and place mozzarella in the center.

Boil water with baking soda. Drop each pretzel in for 30 seconds on each side to achieve a chewy crust.

Preheat oven to 425°F. Place pretzels on a parchment-lined baking sheet, sprinkle with sea salt, and bake for 20 minutes until golden.

Allow to cool slightly before serving. Brush with melted butter for added richness, best served warm.