Warm milk in a microwave safe bowl in microwave (or alternately over stove top in a small saucepan) until temperature of milk reaches 110 degrees, about 1 1/2 - 2 minutes on HIGH power.
Pour milk along with yeast into the bowl of an electric stand mixer and whisk together until yeast has dissolved, let rest 5 minutes. Add brown sugar, 4 tbsp softened butter, 1 cup flour and 2 tsp fine sea salt to milk mixture and using the whisk attachment, stir until blended.
Switch attachment to a dough hook, add remaining 3 1/2 cups flour and kneaded mixture on medium low speed until elastic.
Mix in up to an additional 1/2 cup flour, as needed, until dough pulls away from the sides of the bowl. Cover bowl with plastic wrap and allow dough to rise in warm place until doubled in size, about 1 hour.
Preheat oven to 450 degrees. Line two baking sheets with Silpats or parchment paper (alternately you could grease them). Punch dough down several times to release any air pockets.
Divide dough into 12 equal pieces* and cover loosely with plastic wrap.
Roll each piece out into a long, thin rope about 32 - 36 inches long**. Form dough rope into a pretzel shape.
In a shallow bowl, whisk together baking soda and warm water then fully immerse pretzel into water mixture, lift and allow excess water to drip off***.
Place on prepared baking sheet, reshape as needed and sprinkle to taste with coarse salt. Repeat this process with remaining dough.
Bake pretzels in preheated oven 7 - 11 minutes until golden brown (note that you will likely only be able to cook 6 at a time among the two baking sheets) Remove from oven and brush top and bottom of pretzels with melted butter.
Serve warm with optional dipping sauce. Reheat in microwave or in a warm oven once they've cooled, if desired.
Sprinkle with coarse salt to taste and repeat process with remaining dough.
Bake in oven until golden brown then brush with melted butter.
2 cups (470ml) milk (2%)
1 1/2 Tbsp active dry yeast (2 packets)
6 Tbsp (75g) packed light-brown sugar
4 Tbsp (56g) butter, at room temperature
4 1/2 cups (635g) all-purpose flour, plus an up to an additional 1/2 cup as needed
2 tsp fine salt
1/3 cup baking soda
3 cups (710ml) warm water
coarse salt , to taste
6 Tbsp (56g) butter , melted
Dipping sauce for serving , optional*