In a bowl, combine warm water and sugar. Sprinkle yeast on top and let it sit for about 5 minutes until frothy.
In a large mixing bowl, mix flour and salt. Add the yeast mixture and stir to combine. Knead on a floured surface for about 5 minutes until smooth.
Place the dough in an oiled bowl, cover it with a damp cloth, and let it rise in a warm area for about an hour or until doubled in size.
Punch down the risen dough, divide it into equal pieces, roll into ropes (20 inches long), and twist into pretzel shapes.
Preheat oven to 425°F (220°C). Boil water in a pot, add baking soda, and drop each pretzel into the bath for about 30 seconds before transferring to parchment-lined sheets.
Brush with melted butter and sprinkle with cinnamon sugar. Bake for 10-12 minutes or until golden brown.
