Form the Patties: Take the ground chuck and form it into 1/3-pound burger balls.
Smash the Patties: Using a burger press, smash each ball into a flat patty.
Season: Generously season the patties with SPG rub.
Preheat the Griddle: Get your griddle nice and hot.
Sear the Patties: Place the patties on the hot griddle and sear for 4 minutes on the first side.
Flip and Add Cheese: Flip the patties, season the other side, and place 3 slices of pepper jack cheese on each patty. Cook for 3 more minutes.
Move to Cool Side: Transfer the patties to the cool side of the griddle.
Toast the Buns: Place Texas toast buns on the griddle (reduce the griddle temp) and let them toast for 3-5 minutes until golden.
Assemble: Add a scoop of the jalapeño popper mixture on top of the patties, stack the double patties, and top with the second bun.
Final Toast: Toast both sides of the sandwich and serve hot.