Fill a large pot 3/4 of the way up with salted water. Wash and dry the fresh produce. Quarter the lime(s). Remove any husks and silks from the corn. Cut off and discard the stem of the pepper(s). Halve lengthwise; remove the ribs and seeds, then medium dice. Thoroughly wash your hands, knife, and cutting board after handling. In a bowl, combine the mayonnaise and the juice of 2 lime wedges (or 4 wedges for 4 servings). In a separate bowl, combine the guacamole and the juice of the remaining lime wedges.

In a medium nonstick pan (or large for 4 servings), heat a drizzle of olive oil on medium-high until hot. Add the diced pepper(s) in an even layer. Cook, without stirring, 2 to 3 minutes, or until lightly browned. Add the beef. Cook, stirring frequently and breaking the meat apart with a spoon, 4 to 5 minutes, or until browned. Carefully drain off and discard any excess oil. Carefully add the guajillo sauce and 2 tablespoons of water (or 4 tablespoons for 4 servings). Cook, stirring constantly, 1 to 2 minutes, or until slightly thickened and the beef is cooked through. Turn off the heat.

Meanwhile, add the corn cobs to the pot of boiling water. Cook 3 to 4 minutes, or until bright yellow and slightly tender. Turn off the heat. Drain thoroughly and pat dry with paper towels.

Place the tortillas on a work surface. Top one half of each tortilla with the cheddar and monterey jack and filling; season with salt and pepper. Fold the tortillas in half over the filling. Rinse and wipe out the pan used to make the filling. In the same pan, heat a drizzle of olive oil on medium until hot. Working in batches if necessary, add the quesadillas. Cook 2 to 4 minutes per side, or until golden brown and the cheese is melted (if the pan seems dry, add a drizzle of olive oil before flipping). Transfer to a cutting board and immediately season with salt. When cool enough to handle, carefully halve each quesadilla. Serve the quesadillas with the cooked corn and guacamole on the side. Top the corn with the lime mayo and cotija. Enjoy!