Preheat oven to 400℉ and line a baking sheet with parchment paper. Arrange salmon fillets in a single layer and spray lightly with oil. Season with salt & pepper and bake 11-14 minutes, until opaque.
While the salmon bakes, drain and rinse the corn and beans. Cut open avocados and remove pits; dice in half-inch chunks. Add corn, beans and avocado to a large mixing bowl. Once salmon is cooked, remove from oven and allow to cool a few minutes. Add salmon to bowl and use a fork to break it up.
Add olive oil, salt, pepper, cumin, garlic powder and lime juice to bowl and toss until everything is combined. Be careful not to smash everything together.
Taking one tortilla at a time, assemble burritos. Place a handful of lettuce in the center, and layer with a generous scoop of the salad. Add a scoop of greek yogurt or sour cream on top. Fold the tortilla in at the short ends and roll until complete.