San Antonio Squash Casserole

San Antonio Squash Casserole
(makes 8 servings)
6 tablespoons butter, divided
1 medium onion, coarsely chopped
1 small red bell pepper, coarsely chopped
1 small green bell pepper, coarsely chopped
2 jalapenos, seeded and finely diced
2 pounds yellow squash, sliced, steamed, drained, and cooled
1 cup diced Velveeta cheese
½ cup shredded Cheddar cheese
½ cup shredded Monterey Jack cheese
1 teaspoon kosher salt
½ teaspoon ground black pepper
2 ½ cups crumbled Ritz crackers

Preheat oven to 325 degrees. Spray a 2-quart baking dish with nonstick cooking spray; set aside.
In a large pan, melt 3 Tablespoons butter over medium heat. Add onion, red bell pepper, and green bell pepper; cook, stirring frequently, until tender. Add jalapeno, and cook for 5 minutes. Stir in squash. Fold in cheeses, salt and pepper.
Spoon squash mixture into prepared baking dish; sprinkle with crackers. Melt remaining 3 tablespoons butter and drizzle over crackers. Bake for 20 minutes or until hot and bubbly. Cool for 10 minutes before serving.