Rinse and drain the black beans, then pat them dry with a paper towel to ensure the burger holds its shape.
In a medium bowl, mash the black beans with a fork until mostly smooth but still slightly chunky for texture.
Add the ground turkey, egg white, breadcrumbs, salt, pepper, garlic powder, onion powder, and cumin to the bowl.
Mix the ingredients by hand until just combined and form into a single large, even patty.
Heat a non-stick skillet over medium heat and cook the patty for 5-6 minutes per side until the internal temperature reaches 165°F.
While the burger cooks, mash the avocado with the Greek yogurt and lime juice in a small bowl until creamy and smooth.
Toast the sprouted grain bun in the skillet or a toaster until lightly golden and fragrant.
Assemble the burger by placing the lettuce and tomato on the bottom bun, followed by the patty and a generous dollop of avocado crema.