Preheat your oven to 400 degrees and line a baking sheet with tinfoil.
Slice the squash in half and scrape out the seeds. Rub the insides with the olive oil and sprinkle with salt and pepper.
Bake the squash, cut-side up until fork tender, about 45-55 minutes. Set aside until cool enough to handle, about 10-15 minutes.
Place a large colander over a bowl and line the inside of the colander with paper towel. Scrape the squash out of the shell and place it into the colander to absorb some of the moisture. Let it sit for about 10 minutes.
In a large bowl, whisk together the pizza sauce, tomato paste, egg, Italian seasoning, salt and a pinch of pepper.
Using another paper towel, press the top of the squash to really get all the moisture out. Then, dump it into the bowl with the tomato mixture. Add in 2/3 cup of the cheese and stir until well mixed.
Rub a 9x9 inch pie plate with olive oil and then place half of the squash mixture into it, pressing out flat and evenly.
Place 7 of the ham slices onto the spaghetti squash in a single layer. Place the rest of the squash into the pie plate and gently press out evenly to cover the ham.
Bake until the squash feels set, about 25 minutes.
Sprinkle the remaining cheese on the middle and the squash, leaving the edge to free to look like crust. Then, rip up the remaining ham slices and sprinkle them on top. Finally, sprinkle on the pineapple tid-bits.
Bake until the cheese is melted, about 5-10 minutes.