Preheat oven to 350 degrees Fahrenheit.

Peel and cut butternut squash into 1/3-1/2" pieces. Toss in olive oil, salt and pepper. Spread into a single layer on a baking sheet and bake ~25-30 minutes or until lightly browned and tender. Set aside.

Pour pinto beans into a bowl and stir in chipotle sauce and mash mixture with a fork or potato masher until most of the beans are broken apart and mixture is spreadable.

To assemble quesadillas, arrange 1/3 of the bean mixture, ~1/4 cup cubed butternut squash, 1/2 cup spinach, and 2/3 cup of cheese on one half of a tortilla. Fold tortilla in half.

Spray a nonstick skillet with cooking oil. Gently slide folded tortilla onto skillet and heat over medium low heat until bottom is lightly browned. Flip tortilla over and repeat on the other side until lightly browned and cheese is melted.

Serve with salsa and sour cream.