In a 1-quart glass jar, mix ¼ cup [55 g] dark brown sugar with 1 cup [8 oz] warm water until dissolved. Add 2 ¼ tsp [7 g] yeast and stir gently. Let sit until frothy, about 5 minutes.
In the bowl of a stand mixer, add 3 ¼ cups [415 g] flour and 1 rounded Tbsp coarse kosher salt and mix with your hands. Add 4 Tbsp [55 g] melted unsalted butter and the yeast mixture to the flour and knead with a dough hook on medium speed until smooth and elastic, about 5 to 6 minutes. Shape the dough into a ball, return to the mixing bowl, cover with plastic wrap and refrigerate overnight, about 6 to 8 hours.
Line two baking sheets with parchment and spray generously with nonstick cooking spray. Turn the dough out on a work surface and divide into 12 equal pieces. Roll each piece into a 22-inch coil leaving the center a little thicker. Shape the pretzels by placing the dough in a U-shape in front of you. Cross the two ends and repeat once more. Fold the twisted ends over itself and press down into dough to form the pretzel shape. Transfer to the prepared baking sheets. For that classic look, use a sharp paring knife or razor blade to make a 1/4 inch deep slit in the thickest part of each pretzel. Adjust the shape as needed and repeat with the remaining coils. Gently cover the pretzels with plastic wrap and let rise until noticeably puffy, about 20 to 30 minutes.
Preheat the oven to 450°F (232°C) with the racks placed in the top third. Bring 7 cups [56 oz] of water, 1 cup [8 oz] beer, the remaining ¼ cup [55 g] brown sugar, and ½ cup [125 g] baking soda to a boil in a medium pot. Simmer each pretzel, one at a time, in the water for about 30 seconds using a wide slotted spoon or spatula to submerge them. Transfer back to the prepared baking sheets using a slotted spoon. Once all the pretzels are ready, lightly beat an egg yolk in a small bowl and brush with the egg wash. Sprinkle each with finely grated gruyere cheese.
Bake until the pretzels are nice and dark brown all over, about 10-15 minutes. Transfer to a wire rack and let cool slightly. Slice the pretzels in half, layer some speck, and sandwich back together. Serve warm.