Take out the butter from the refrigerator and let it soften for 15 minutes. Mix all ingredients except salt, butter, and egg. Mix the dough in a dough mixer for 3 minutes on medium speed, or until all flour is hydrated.

Add one egg. Save the other egg for brushing the buns. Add butter in small pieces, one by one. Wait until every piece is incorporated into the dough before you add the next.

Run the dough in the mixer for 6-8 minutes. Add salt and run the dough until elastic. Do window pane test. If necessary run it in the mixer for some additional minutes.

Let the dough ferment for 2 - 3 hours at room temperature.

Pour out the dough on a lightly floured working surface. Divide the dough into pieces of appropriate size. 7 for pulled pork and 10 for hamburgers. shape each piece into a ball. I used the same technique as when I'm shaping a boule. Just make sure that the surface is taut.

Place the balls on a baking sheet with parchment paper. Let them rise for an hour, covered. A kitchen towel is Ok, but a big plastic tray that covers all the balls is better Pre-heat the oven to 480ºF / 250ºC. Place an extra baking sheet in the bottom of the oven.

Press gently with a finger against the dough. If the hole disappears completely when you remove your finger, the dough is under-proofed. If the hole springs back halfway, the dough is ready. Whisk the remaining egg with some milk and brush is on the balls. Sprinkle some poppy seed on top (optional)

Place the baking sheet with balls in the oven and pour some water on the sheet below to get some steam. Bake for 20 minutes. Turn down the temperature if necessary.

Let the buns cool on a wire rack.

Mix all spices and store in air tight container.

Fry the onion, garlic and cumin in oil on medium heat for 1 minute. Add vinegar and the rest of the ingredients. Let it boil until you get a thick sauce.

Pre-heat the oven to 230ºF / 110ºC Apply the rub on the meat and place it in a casserole or baking dish. Cook until the inner temperature has reached 230ºF / 95ºC. Shred the meat with two forks before serving with hamburger buns and BBQ sauce.