In the bowl of a stand mixer fit with the dough hook, combine the warm water, brown sugar and yeast. Let it sit for at least 5 minutes until foamy.
Once it has foamed, add the flour, salt and melted butter to the bowl. Mix on low speed until the flour is incorporated and then turn the mixer to medium and knead the dough for 5-7 minutes. The dough should be smooth, bounce back when indented with your finger and not be sticky. If the dough is sticky, add more flour by the tablespoon until it is not sticky but still slightly tacky.
Remove the dough from the bowl and either clean and oil the same bowl or oil another bowl and place the dough into it to rise, covered, in a warm place until doubled in size, about an hour.
Once the dough has risen, punch it down and scrape it onto a lightly oiled (or use cooking spray) surface. Form the dough into a rough rectangle and then divide the dough into 8 equal pieces (about 118-130 grams each if using a scale) using a knife or pizza cutter.
At this point, preheat the oven to 450 degrees and prepare 2 baking sheets with parchment paper and cooking spray. Prepare the baking soda bath by placing 8 cups of water and ½ cup of baking soda into a large deep saucepan, roasting pan or large dutch oven.
Roll out each dough piece, one at a time, to about a 20 to 22 inch long rope.
Shape the rope into an upside-down U. Cross the ends over each other and then twist them once. Take and ends and flip them up to the bottom of the U shape, pinching each end onto the U to stay. (See the pictures in the post!)
Do this with each dough ball, placing them onto the baking sheets.
Bring the baking soda/water mixture to a boil and one or two at a time, place each pretzel gently into the boiling solution and boil for 30 seconds. There is no need to turn it. Use a large slotted spoon or slotted spatula to lift them out of the baking soda bath, shaking off any excess water and placing them back onto the baking sheets.
Combine one beaten egg with a teaspoon of water and use a pastry brush to brush the top of each pretzel with the egg wash.
Bake the pretzels for 9-11 minutes until deep golden brown. Let the pretzels cool for about 5 minutes and then brush each with the melted butter. Combine the sugar and cinnamon in a bowl and sprinkle the cinnamon sugar over the tops, shaking off any excess.
The pretzels are best eaten warm from the oven.