Mash beans in a medium bowl until chunky. Add goat cheese, tomato, corn, scallions, and oregano. Season with salt and pepper, and stir until well combined.
Heat a grill pan over medium heat. Spread 1/2 cup bean mixture evenly over 1 tortilla, and top with another tortilla. Repeat with remaining bean mixture and tortillas.
Raise heat to medium-high. Grill quesadillas, 1 or 2 at a time, until grill marks appear and filling is hot, about 2 minutes per side. Cut into wedges and serve warm.
To give the quesadillas a smoky flavor, cook them on an outdoor grill rather than in a grill pan, until the cheese melts and the tortillas are crisp.