Heat a large nonstick skillet with 2 tablespoons of oil over medium-high heat. Cook the onions and peppers until they begin to soften and have started to brown on the edges. Add in the beef and cook until no longer pink. Season with cumin, chili powder, salt and salsa. Simmer for 5 minutes. Remove from heat and set aside to cool.
Make 17 quesadillas by placing 1/4 cup of shredded cheese onto each tortilla, fold in half and set aside.
Spray Bundt pan with nonstick cooking spray. Line the pan with 11 quesadillas, making sure that they overlap on the edges. Sprinkle 1/2 cup shredded cheese into the bottom of the pan. Add the cubed Velveeta and the Rotel.
Cover with a layer of three quesadillas before moving on to the next layer. Add the cooled meat mixture on top of the quesadilla layer and then top with more cheese and then the last 3 quesadillas. Press down firmly with your hands to make sure everything is compact. Bake for 45 minutes.