In a large mixing bowl, combine the lukewarm water, yeast, and 2 tablespoons of sugar. Allow it to sit for about 5 minutes or until foamy.

In a separate bowl, mix together the flour, salt, and ground cinnamon. Once the yeast mixture is ready, add the pumpkin puree to it.

Gradually add the dry ingredients to the wet mixture while mixing until a dough forms. Knead the dough on a floured surface for about 5-7 minutes until smooth, or use a stand mixer with a dough hook for about 5 minutes.

Shape the dough into a ball and place it in a greased bowl. Cover with a clean kitchen towel and let it rise in a warm place for about 1 hour or until doubled in size.

Preheat the oven to 425°F (220°C) and line a baking sheet with parchment paper.

In a pot, bring about 10 cups of water to a gentle boil and add the baking soda.

Once the dough has risen, punch it down gently and divide it into 12 equal portions. Roll each portion into a long rope, then twist into a pretzel shape.

Carefully drop each pretzel into the boiling water for about 30 seconds, then remove with a slotted spoon and place on the prepared baking sheet.

In a small bowl, whisk together the egg and 1 tablespoon of water, then brush the mixture over each pretzel.

In another bowl, combine ½ cup sugar and 2 teaspoons cinnamon. Sprinkle this mixture over the pretzels.

Bake the pretzels in the preheated oven for about 12-15 minutes or until golden brown. Remove and brush with melted butter immediately after baking.