In a large bowl, combine the warm water and sugar, stirring until dissolved. Sprinkle the yeast over the top and let sit for about 5 minutes, until frothy.
Add the flour and salt to the yeast mixture, and stir until a dough begins to form. Knead the dough on a floured surface for about 5 minutes, until smooth and elastic.
Place the dough in a greased bowl, cover with a clean kitchen towel, and let rise in a warm place for about 1 hour, or until doubled in size.
Preheat your oven to 425°F (220°C). Line a baking sheet with parchment paper.
Once the dough has risen, punch it down and turn it out onto a floured surface. Divide the dough into small pieces (about 1 inch each). Roll each piece into a small ball.
In a large pot, bring about 10 cups of water to a boil and add the baking soda. Carefully drop the pretzel bites into the boiling water, cooking for about 30 seconds on each side. Use a slotted spoon to transfer them back to the parchment-lined baking sheet.
Brush the boiled pretzel bites with melted butter and sprinkle with the cinnamon sugar mixture (combine ½ cup sugar and 2 teaspoons cinnamon in a small bowl).
Bake in the preheated oven for 12-15 minutes, or until they are a golden brown color.
Let cool slightly before serving, then enjoy these warm and fluffy bites!