Combine warm water and sugar in a large bowl, sprinkle the yeast over top, and let it sit for 5-10 minutes until foamy.
Add the melted butter to your yeast mixture, then gradually incorporate the flour and salt. Mix until a shaggy dough forms, then turn out onto a lightly floured surface.
Knead for 5-7 minutes until smooth and elastic—the dough should spring back when poked gently with your finger.
Place your dough in a lightly oiled bowl, turning once to coat, then cover with a damp towel or plastic wrap. Let it rise in a warm spot until doubled in size, about 1 hour.
Preheat your oven to 450°F and line two baking sheets with parchment paper or silicone mats.
Divide the dough into 8 equal pieces. Roll each piece into a 24-inch rope, form a U-shape, cross the ends over each other twice, then fold down and press onto the bottom curve.
Bring 8 cups of water to a gentle boil in a wide pot, then carefully add the baking soda (it will bubble vigorously).
Gently lower each pretzel into the bath for 30 seconds, flipping halfway through.
Transfer the bathed pretzels to prepared baking sheets, brush with egg wash, and sprinkle with coarse salt or your chosen topping.
Bake for 12-15 minutes, rotating pans halfway through, until deeply golden brown. The internal temperature should reach 190°F for perfectly baked pretzels.