In a small bowl, combine warm water, yeast, and sugar. Let sit for 5 minutes until foamy.

In a large bowl, mix together flour and salt. Pour the yeast mixture and melted butter into the flour. Stir until a shaggy dough forms, then knead by hand or with a stand mixer for about 8-10 minutes until smooth and elastic.

Place dough in a greased bowl, cover with a damp towel, and let rise for 30-45 minutes until doubled in size.

Preheat oven to 425°F. Line two baking sheets with parchment paper. Punch down dough and divide into 8 equal pieces.

Roll each piece into a rope about 20 inches long. Shape into a pretzel by forming a loop, crossing the ends, and tucking them back through the bottom of the loop.

Bring 2 quarts of water to a boil and stir in the baking soda. Working in batches, carefully drop pretzels into the boiling water and cook for about 20-30 seconds until they float, then remove with a slotted spoon.

Place boiled pretzels on the prepared baking sheets. Brush immediately with melted butter and sprinkle generously with coarse salt and optional sesame seeds or seasoning.

Bake for 12-15 minutes until golden brown. Cool slightly on the baking sheet before serving warm with cheese dip or mustard.