Preheat grill to high. Preheat oven to 375 degrees F.
Mix diced chipotle, lime juice and sour cream, and refrigerate for 1 hour.
Over medium flame or on a grill pan, roast corn. Let cool and cut kernels off cob.
In a medium saute pan over medium-high heat, add olive oil, jalapenos, red onions, and black beans. Saute until the onions are translucent. Add the tomatoes, corn kernels and roasted bell pepper. Stir and saute for 3 minutes and add salt, pepper, cumin and 3 tablespoons of cilantro. Remove the pan from heat and let rest.
Evenly distribute mixture, the remaining cilantro and cheeses among 4 tortillas. Top with remaining tortillas.
Place tortillas on a baking sheet and place in the oven. Cook for about 10 minutes, until cheeses have melted and the quesadillas are warmed through. Cut each into 6 pieces.
Serve with chipotle sour cream garnished with scallions.