Combine the warm water and salt in the bowl of a stand mixer and sprinkle the yeast on top. Allow it to sit for about 5 minutes.
Add the pumpkin, sugar, cinnamon, and 5 1/2 cups flour and butter and using the dough hook attachment, mix on low speed until well combined. If dough is too wet add, another 1/4-1/2 cup flour. Change to medium speed and knead about 5 minutes until the dough is smooth and pulls away from the side of the bowl.
Remove the dough from the bowl, and place the dough in a glass bowl oiled with vegetable oil. Cover with plastic wrap and let rise in a warm place for approximately 50 to 55 minutes or until the dough has doubled in size.
Divide the dough into 16 pieces. Roll out each piece of dough into a 12-inch rope. Using a sharp knife, cut rope into 1-inch pieces.
Preheat the oven to 450°F. Using a large saucepan, fill with water. Bring the water to a boil and add the baking soda.
Place the pretzels into the boiling water for 30 seconds each. Remove them from the water using a large flat spatula. Place pretzels on baking sheet lined with parchment paper or silpat mat.
Beat one large egg yolk. Brush the top of each pretzel bite with the beaten egg yolk. (I didn't do this but next time I think I want to coat the pretzels with a cinnamon sugar mixture before baking). Bake until golden brown in color, approximately 6-8 minutes.
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.