Prepare the Dough: In a large mixing bowl, combine warm water (around 110°F), brown sugar, and yeast. Let the mixture sit for about 5 minutes until it becomes frothy. Next, stir in melted butter and salt, and gradually add all-purpose flour until a soft dough forms. Knead the dough on a floured surface for 8-10 minutes until it’s smooth and elastic.

First Rise: Transfer the kneaded dough into a greased bowl, making sure to coat it lightly to prevent sticking. Cover the bowl with a clean kitchen towel or plastic wrap and place it in a warm spot. Allow the dough to rise for about 1 hour, or until it has doubled in size.

Shape the Buns: Once the dough has risen, punch it down gently to release any air bubbles. Divide the dough into 8-10 equal portions and shape each piece into a round bun. Place the shaped buns on a greased baking sheet and let them rest for 15 minutes.

Boil the Buns: In a large pot, bring water to a rolling boil, then carefully stir in baking soda, ensuring it dissolves completely. Using a slotted spoon, gently lower each bun into the boiling water, allowing them to boil for 30 seconds on each side.

Prepare for Baking: After boiling, transfer the buns back onto a parchment-lined baking sheet. Brush each bun with an egg wash made from a beaten egg for a glossy finish. Score the tops with a sharp knife and sprinkle generously with coarse sea salt.

Bake: Preheat your oven to 400°F, then bake the buns for 18-22 minutes. Once done, remove the soft pretzel buns from the oven and let them cool on a wire rack.