In a large bowl, mix the warm water, brown sugar, and yeast. Let it sit for about 5 minutes until it's foamy.

Add olive oil, salt, and flour to the bowl. Stir until you have a shaggy dough. Knead it by hand or with a mixer for about 5–7 minutes until smooth and elastic.

Place the dough in a lightly greased bowl, cover it with a towel, and let it rise in a warm spot for 1 hour or until it has doubled in size.

While the dough is rising, prepare the mozzarella, rosemary, and parmesan. Line two baking trays with parchment paper for easy cleanup.

Once risen, punch down the dough and divide it into 8 equal parts. Roll each piece into a 14-inch rope, place the mozzarella in the center, pinch the dough to seal it, and twist into a pretzel shape.

Preheat your oven to 425°F (220°C). In a large pot, bring 9 cups of water and ½ cup of baking soda to a boil.

Carefully drop each pretzel into the bath for about 20 seconds, then use a slotted spoon to remove and place them back on the tray.

Brush each pretzel with the beaten egg and sprinkle with rosemary, parmesan, and coarse salt.

Bake for 12–15 minutes until deep golden brown and puffy. Let them cool for a few minutes before serving.