To prepare this recipe without an Instant Pot, halve the squash lengthwise and scrape out seeds. Brush cut-sides with 1 tbsp olive oil. Place squash cut-sides down on a foil-lined rimmed baking sheet and bake in a 400°F oven 45 min.–1 hour., until very tender. Let cool slightly. Using a fork, shred strands. In a 10-inch skillet, heat the oil on medium-high. Cook the bacon 4 min., until almost crisp. Stir in the spinach in batches until wilted. In a bowl, toss spaghetti squash with bacon mixture and remaining ingredients.