In a medium bowl, mash butter beans. Mix in onion, jalapeno pepper, crushed crackers, egg, cheese, garlic powder, salt, and pepper. Divide into 4 equal parts, and shape into patties.
Heat oil in a large skillet over medium-high heat; use more or less oil to reach 1/4 inch in depth. Fry patties until golden, about 5 minutes on each side.