Add 1 tablespoon olive oil to an electric pressure cooker. Turn to saute for 14 minutes, add the beef and pork, sprinkle with the salt, garlic powder, and Italian seasoning, and cook, stirring occasionally, until browned.
Add the tomato sauce and stir to combine, scrapping any browned bits from the bottom of the pot.
Add the steamer rack trivet on top of the sauce. Drizzle the remaining 1 tablespoon olive oil over the spaghetti squash halves. Place the spaghetti squash halves in the steamer trivet, avoiding any significant overlap. If the pieces are too big, cut each in half and arrange in the basket, avoiding overlap.
Secure the lid, select the manual setting, and set it to high pressure for 25 minutes.
When the pressure cooker timer is done, quick release the pressure.
Carefully remove the steamer trivet, and place the cooked squash on a cutting board. When cool enough to handle, use a fork to scrape the inside of the squash against the grain, so it separates into strands. If the squash seems watery, place it in a strainer and gently press down to remove any excess liquid.
Serve the spaghetti squash topped with meat sauce, plus basil and red pepper flakes to taste.