Season brisket with desired spices, such as onion powder, garlic powder, dry mustard, cayenne pepper, chili powder, brown sugar, salt, and pepper.
Cook brisket using your favorite method (such as braising in an oven or slow cooker, or traditional smoking methods).
Slice or chop cooked brisket into small pieces and pile onto sandwich rolls.
Top with barbecue sauce and jalapeños. Add cheese or other toppings if desired.