Add water to a large 4QT stockpot and bring to boil.
While the water is boiling, roll out the dough and divide into 6-8 equal pieces. Roll out each piece into ¾-1” diameter ropes.
Take a rope and using a rolling pin, flatten the pretzel dough lengthwise. You're looking for the dough to be approximately 1½ foot long, and roughly 1½" to no more than 2" wide, flattened.
Take a spoonful of the brownie batter and roll into a log. I used approximately ⅓" thick diameter logs. The batter is soft and pliable so you'll probably need to do multiple small logs to build the brownie batter center. Take care not to add too much. Lay the brownie batter logs in the center of the rolled pretzel dough.
Use your finger dipped in water and trace one long side of the dough. Gently fold the dough around the brownie batter log center, pinching the dough together firmly around the chocolate center. The water should help with the seal. Pinch together and roll out to an even rope again.
Twist into a pretzel shape by tying a knot, and then arrange the ends neatly. You can also give the two ends an extra twist together, but I find that these are chunky boys with the filling, so I mostly skip the twist. You can also make any other shape you prefer. Set aside the pretzel under a damp towel or cloth.
Repeat the previous 4 steps with the remaining pretzel dough. You may have some brownie batter left over, I had about 3 Tbsp leftover. You can simply store it and snack on it later!
Once your pretzels are rolled and folded, ready your baking sheet with parchment paper. Add the baking soda to the boiling water (note that this will bubble and froth violently when first added.) Using a slotted spoon, lower the pretzels into the boiling water in batches.
The pretzels will sink when they are first added to the water, but after 1-2 minutes should float to the top. Once they are floating, use a slotted spoon to transfer to your parchment paper lined baking sheet. Try to drain as much of the liquid as possible, but it's ok to be a little messy on the sheetpan.
Brush each pretzel generously with egg wash. Sprinkle with sea salt or maldon salt on top to taste. Bake 12-14 minutes (they make take longer depending on their thickness). You're looking for a nice golden brown color. Serve warm with caramel or chocolate dipping sauce, or enjoy plain!b