Make the pretzels: Warm the milk in microwave (about 30 seconds); pour into a medium bowl & add yeast. Let it sit about 2 minutes; stir in the brown sugar and 1 cup flour with a wooden spoon. Add 2 tablespoons softened butter; mix. Add the remaining 1¼ cups flour and salt to make a sticky dough. Turn onto a lightly floured surface & knead, adding more flour if needed, knead about 5 minutes. Shape into ball, place in a lightly greased bowl and cover with plastic wrap or kitchen towel. Let rise until doubled in size, about 1 hour.
Preheat the oven to 450 degrees and line baking sheets with parchment paper, non-stick mat or grease with butter.
Divide dough into 6 pieces if you want big pretzels (12 pieces if you want smaller ones). Use a lightly oiled surface to roll and stretch each piece with the palms of your hands into a 30-inch rope. Form each rope into a pretzel shape.
For the soda bath: dissolve the baking soda in warm water in a shallow baking dish. Dip each pretzel in it, then arrange on the prepared baking sheet.
Bake 10 to 12 minutes or until tops are turning golden brown.
Melt 4 tablespoons of butter in a shallow dish. Brush pretzels with butter or dip them in it. Sprinkle with cinnamon/sugar mix.