Combine mayonnaise and chipotle, set aside.

Drain and rinse the black beans; mash them in a medium bowl until thick and pasty.

Finely chop cilantro, scallions, and garlic, then add to the mashed beans along with oats and spices.

Mix everything thoroughly, then divide into four patties and shape with oiled hands.

Wrap each patty in wax paper and freeze for at least 2 hours.

Heat a skillet over medium heat, lightly spray with cooking spray, and cook frozen patties about 7 minutes per side.

As an alternative, grill or bake in preheated oven at 375°F for about 20 minutes until browned.

Serve on buns with sliced avocado and a dollop of chipotle mayo.