In a large mixing bowl, combine 1 1/2 cups of warm water with 2 tablespoons of light brown sugar. Sprinkle the active dry yeast over the top and let it sit for about 5-10 minutes until it becomes frothy.
Once your yeast mixture is frothy, add the melted unsalted butter and kosher salt. Gradually stir in 4 to 5 cups of all-purpose flour, one cup at a time, until a soft dough forms.
Transfer the dough onto a floured surface and knead for about 5-7 minutes, until smooth and elastic. Form the dough into a ball and place it in a greased bowl, cover it, and let it rise for about an hour.
Preheat your oven to 425°F (220°C). Punch down the dough and roll it out into a rectangle about 1/2 inch thick. Cut the dough into small squares, fill with pepperoni and mozzarella, fold, and seal.
In a large pot, boil 5 quarts of water and add 3/4 cup of baking soda carefully. This creates the pretzel flavor and color.
Using a slotted spoon, drop each filled pretzel bite into the boiling baking soda bath for about 30 seconds. Remove and place on a parchment-lined baking sheet.
Brush each pretzel bite with the egg wash and sprinkle coarse sea salt on top. Bake for about 12-15 minutes, or until golden brown.
Let the pretzel bites cool slightly before serving with warm pizza sauce for dipping.