Place spiralized squash and apple on a rimmed baking sheet. Drizzle with the olive oil and toss around a bit with tongs to coat. Spread evenly on baking sheet and sprinkle with salt. Roast in oven for 10 minutes.
Remove squash and apple from oven and let cool on baking sheet for about 3 to 4 minutes. Transfer to serving bowl and add spinach. Add salad dressing and toss everything until evenly coated
Top with feta cheese and pumpkin seeds (pepitas), roasted or raw