Add plantains; cook 3 min. on each side or until tender and lightly browned on both sides. Use slotted spoon to remove plaintains from skillet; drain on paper towels. Flatten plantains with back of spatula to 1/4-inch thickness; return to skillet. Cook 1 min. on each side or until golden brown on both sides.
Remove from skillet; drain on paper towels.
Spread avocado mixture onto 4 plantain slices; top with lettuce, tomatoes, bacon, cheese and remaining plantain slices.