Place your warm water, salt, and sugar in your mixing bowl. Add the yeast, and stir. Add 2 cup of flour and mix until thoroughly combined. Add the butter and mix until incorporated. Add the remaining 2 1/2 cup flour and stir until the dough is a uniform consistency. Knead with a stand mixer 5-7 minutes or by hand 10-20 minutes until the dough is soft and uniform.
Place a damp cloth over the bowl and let rise in a warm place for 1 to 1 1/2 hours until doubled. Prepare two baking sheets while the dough is rising by greasing lightly.
Cut the dough into 12 equal size pieces (about 3.4 ounces each). Let rest for a few minutes while preparing the baking soda bath. Fill a large heavy pot about 2/3 full of water and add 2/3 cup baking soda. Bring to a boil while shaping your pretzels. If making traditional pretzels, roll into 24 inch ropes then flip into the pretzel shape. If making Mickey Mouse ears, poke a hole in the middle, stretching out the head from that initial circle, being sure to pull out two lumps of dough for the ears. Place each finished pretzel onto your baking sheet.
Preheat your oven to 450 degrees. Once all pretzels have been formed, beat your egg yolk with 1 tablespoon water to form an egg wash and set aside. Drop pretzels into your baking soda bath one at a time, letting cook for about 30 seconds and flipping halfway through before placing back on your baking sheet. This is what gives your pretzels some of its traditional taste and texture.
1 egg yolk, 2/3 cup baking soda
Once half your pretzels have been boiled off, brush them with the egg wash and add salt to the top. Place them in the oven and bake for 12 minutes at 450 degrees until golden brown. While they are baking, prepare the other 6 pretzels and bake once the first batch is complete.