In a large mixing bowl, combine warm water and yeast. Let stand for 10 minutes, until a creamy foam develops on the surface.
In a smaller mixing bowl, combine flour, salt, and brown sugar.
Add 4 Tbsp softened butter and dry ingredients to water / yeast mixture.
Stir with a wooden spoon until the dough comes together.
Lightly dust a work surface with flour. Turn dough out on floured surface and knead until dough is smooth and elastic, 8 to 10 minutes, adding additional flour a bit at a time if needed to prevent sticking.
Transfer dough to a lightly oiled bowl and cover with a kitchen towel.
Let dough rise in a warm place until doubled, ~2 hours.
When dough has risen, heat oven to 450 F / 232 C.
Line two sheet pans with parchment paper or rub them with oil.
While oven is heating, fill a large saucepan (I often use my wok for these) with 8 cups water and baking soda. Bring mixture to a boil (as the water heats, it will develop large foam bubbles on the top).
While water is coming to a boil, punch down dough and divide into 6 sections.
Divide each dough section in half and roll each half into a 12-inch rope.
Cut each rope in to 6 2-inch pieces. (Note: This should make 72 pretzel bites, but it’s fine to make them slightly larger and have fewer. If you make larger bites, bake them for 2 to 3 minutes longer than the time listed below.)
Working with 12 pretzel bites at a time, carefully drop them into the boiling water / baking soda mixture. Boil for 30 seconds and then use a slotted spoon to transfer them to prepared sheet pans.
Bake pretzel bites until deep golden brown, rotating the pans halfway through baking, 8 to 10 minutes.
While pretzel bites bake, melt 4 Tbsp butter in one medium bowl. Combine sugar, cinnamon, and pumpkin pie spice in a second medium bowl.
When pretzel bites are finished baking, allow to cool slightly on the sheet pans.
Working in batches, drop warm pretzel bites into butter and then sugar mixture, turning to coat on all sides.
Serve pretzel bites on their own or with warm caramel sauce for dipping. They’re best served warm but, once cool, they can be kept at room temperature for a couple hours before serving.