Preheat the oven to 450F.
In a small bowl, mix olive oil and garlic. Spread the mixture evenly on the bread slices (just the inside part of the bun). On a medium baking sheet, arrange the slices evenly and broil 5 minutes, or until slightly brown.
In a separate small bowl, mix together mayo and sriracha.
Spread spicy mayo over the bun. Add lettuce, tomato slices, bacon, and avocado. Top with another bun and enjoy.