In a large Dutch oven, add the potatoes and cover with water. Bring to a boil over medium-high heat; then reduce heat, and simmer until tender about 10 to 12 minutes. Drain well and add to a large bowl.
Mash the potatoes with the garlic and salt and pepper. Fold in 2 1/2 cups of the panko, the egg, cheese, bacon, onion, butter, and the sour cream. Form the potato mixture into 3-inch patties. Put the remaining 1 cup of panko in a shallow dish and dredge the potato patties in the crumbs.
In a large skillet, heat the oil over medium-high heat. Add the potato patties, and cook until brown and crisp, 3 to 4 minutes per side. Arrange on a serving platter and serve immediately.