Preheat oven to 350º. Lightly butter a 13 x 9 in baking dish. Cut the squash in half, lengthwise. Remove and discard seeds. Place squash, upside down, in a shallow baking dish. Prick outer skin with a fork. Add a 1/2 inch of water. Bake for 45 minutes. Turn squash over, bake an additional 20 minutes, or until tender. Remove from oven. Remove squash from shallow baking dish. Set aside until cool enough to handle.

Using a fork, separate squash into strands.

Spoon spaghetti strands into prepared 13 x 9 inch dish. Discard shells.

Heat butter and oil in medium skillet over medium heat. Add garlic, cook 2 minutes. Whisk in flour, season with salt and pepper. Reduce heat to low and cook, stirring constantly, 3 to 4 minutes. Add milk and broth. Continue whisking, raising heat to medium-high

Whisk until mixture comes to a boil and becomes smooth and thick, about 2 minutes. Once mixture becomes thick, remove from heat. Add cubed cheese and mix well or until cheese is melted. Sprinkle crumbled bacon over squash. Stir cheese sauce and pour over bacon and squash. Loosely cover with foil and bake for 45 minutes.

Remove from oven. Sprinkle crushed crackers over squash, dot with cold cubed butter.

Bake for an additional 15 minutes, uncovered, until golden brown and bubbly.