Start by activating your yeast. Combine warm water, sugar, and yeast in a mixing bowl, letting it sit for 10 minutes until foamy. Add salt, chopped rosemary, soft butter, and flour. Knead the dough using a stand mixer or by hand until smooth and elastic. Place it in a warm environment to rise for about an hour, or until it doubles in size.

Once the dough is ready, divide it into 8 equal pieces. Roll each piece into a rope, then flatten it with a rolling pin to create a wide strip. Fill the center of each strip with a mix of mozzarella and Parmesan cheese, then fold the dough over and pinch the edges tightly to seal the cheese inside.

Prepare a pot of boiling water with baking soda. One by one, dip each pretzel into the boiling liquid for about 30 seconds. This step ensures the pretzels will have that signature chewy crust once baked. Remove the pretzels with a slotted spoon and place them on a lined baking sheet.

Brush each pretzel with an egg wash, then sprinkle with a combination of garlic powder, Parmesan, rosemary, and a pinch of black pepper. Bake in a preheated oven at 425°F for 16-18 minutes, or until the pretzels are golden brown. Brush with melted butter after baking for an extra touch of richness.