Step 1

In a bowl, coarsely mash beans with a potato masher. Warm a large skillet over medium-high heat; add corn and cook for 3 to 4 minutes, stirring occasionally, until corn begins to brown. Add corn to bowl with beans.

Step 2

In same skillet, warm oil. Add onion and jalapeño and sauté for 2 minutes. Add garlic and sauté 1 minute longer. Stir mixture into bowl with beans and corn. Let mixture cool to room temperature, about 10 minutes.

Step 3

When cool, stir in cheese and season with salt and pepper. Preheat oven to 200ºF. Spread a tortilla out on a work surface and spread a 1/2-cup portion of bean mixture over half. Fold tortilla in half. Repeat with remaining tortillas and bean mixture. Warm a large skillet over medium-high heat. Cook as many tortillas as fit in skillet, 3 minutes, then flip quesadillas and cook until golden brown and crispy and cheese is melting, 2 to 3 minutes longer. Place quesadillas on a baking sheet and keep warm in oven while you cook remaining quesadillas. Cut into wedges and serve.