1. In a large mixing bowl, dissolve yeast in warm water. Let it sit for about 5 minutes until it becomes frothy.
2. Add sugar and salt to the yeast mixture. Gradually add flour and mix until a dough forms.
3. Knead the dough on a floured surface for about 5 minutes until smooth and elastic.
4. Place the dough in a greased bowl, cover, and let it rise in a warm place for about 1 hour or until doubled in size.
5. Preheat oven to 450°F (230°C). Line a baking sheet with parchment paper.
6. Punch down the dough and divide it into 8 equal pieces. Roll each piece into a rope and shape into a pretzel.
7. In a large pot, bring water and baking soda to a boil. Boil each pretzel for about 30 seconds, then place on the prepared baking sheet.
8. Brush each pretzel with melted butter and bake for 12-15 minutes, or until golden brown.
9. In a shallow dish, mix sugar and cinnamon. Brush warm pretzels with more melted butter and dip in the cinnamon sugar mixture.