01 - Preheat oven to 300°F.
02 - In a small bowl, combine salt, pepper, smoked paprika, garlic powder, onion powder, and cumin. Rub mixture all over brisket.
03 - Heat olive oil in a large oven-safe pot or Dutch oven over medium-high heat. Sear brisket on all sides until browned, about 2–3 minutes per side.
04 - Remove brisket. Add sliced onion and smashed garlic to the pot; sauté 2 minutes. Return brisket to the pot. Add beef broth.
05 - Cover tightly and transfer to oven. Cook for 4 hours, turning halfway through, until fork-tender.
06 - In a saucepan, combine ketchup, vinegar, brown sugar, Worcestershire, mustard, smoked paprika, garlic powder, onion powder, and cayenne. Simmer over low heat for 15 minutes, stirring occasionally, until thickened. Season to taste.
07 - Remove brisket from oven and let rest 15 minutes. Shred meat using two forks, discarding excess fat. Toss shredded brisket with half of the BBQ sauce.
08 - Brush slider buns with melted butter and toast lightly.
09 - Place brisket on bottom half of each bun. Top with cheddar cheese and coleslaw. Drizzle with extra BBQ sauce. Cover with top bun.
10 - Serve immediately.