Cut the squash in two, then scoop out the seeds with a large spoon. Trim any remaining stringy parts of the squash. Flip over each half, and slice squash in one inch pieces.
In a small bowl, whisk together the tofu and soy milk. Set aside.
In a medium saucepan, add brown sugar. Stir over medium heat until sugar starts to melt. Add tofu-soy mixture. When adding the liquid to the brown sugar, the liquid will bubble up and clumps of sugar will form. Keep whisking until the mixture is smooth. The mixture will turn a toasty brown. The brown sugar mixture usually thickens in about 15 minutes. Stir often to keep the caramel from burning and sticking to the pan.
Drizzle caramel sauce over squash. Bake at 375 degrees for 40-45 minutes, or until squash is tender.