Place squash halves in a microwave-safe bowl and cover bowl with plastic wrap. Cook in microwave until flesh is very tender, 12 to 15 minutes.
Pour about 1 inch of oil in a skillet and place over medium-low heat. Fry tortillas in oil until softened and lightly browned, about 10 seconds per side. Drain tortillas on paper towel-lined plates.
Preheat oven to 325 degrees F (165 degrees C).
Spread a thin layer of enchilada sauce into the bottom of a 9x13-inch baking dish.
Sprinkle cinnamon, garlic salt, and black pepper over squash; mash until smooth. Stir black beans and cilantro into squash mixture until filling is well mixed.
Place a tortilla in the bottom of the baking dish; spoon filling down the middle and roll tortilla around filling, keeping it seam-side down. Repeat with remaining tortillas and filling. Stack rolled tortillas on top of each other, if needed. Pour remaining enchilada sauce over tortillas and top with Colby-Jack cheese.
Bake in the preheated oven until cheese is melted, 25 to 30 minutes.