Wash and dry produce. 

Drain and rinse beans. Quarter lime. Roughly chop cilantro. 

Transfer beans to a medium microwave-safe bowl. (Rinse out strainer.) Stir in half the chili powder (you'll use more later), 1 TBSP water (2 TBSP for 4 servings), a drizzle of oil, a pinch of salt, and pepper. Cover with plastic wrap and microwave until warmed through, 1-2 minutes.

Add a squeeze of lime juice; stir to combine.

Drain corn; pat dry with paper towels. 

Heat a drizzle of oil in a large pan over high heat. Add corn and cook, stirring occasionally, until golden brown and lightly charred in spots, 4-6 minutes. TIP: Cover pan if corn begins to pop!

Meanwhile, in a large bowl, combine mayonnaise, half the cotija cheese (you'll use the rest later), remaining chili powder, juice from two lime wedges (four wedges for 4 servings), a big pinch of salt, and pepper. 

Once corn is done, turn off heat. Transfer to bowl with mayonnaise mixture; stir to thoroughly combine. Taste and season with salt and pepper if desired. Set aside until ready to serve. Wash out pan.

Place tortillas on a clean work surface. Evenly divide seasoned beans, Mexican cheese blend, and remaining cotija cheese between bottom halves of tortillas. (TIP: Reserve some cotija cheese for serving if you like!) Fold each tortilla in half to form quesadillas. 

Heat a drizzle of oil in pan used for corn over medium heat. Add quesadillas; cook until tortillas are golden brown and cheese melts, 2-4 minutes per side (depending on the size of your pan, you may need to work in batches). TIP: Lower heat if tortillas begin to brown too quickly.

Cut quesadillas into wedges; divide between plates and dollop with sour cream. Serve esquites on the side. Squeeze remaining lime over esquites. Sprinkle everything with cilantro and serve.