Preheat oven to 400 degrees F and line a baking sheet with parchment paper.
Transfer the cherry tomatoes to the baking sheet. Arrange in an even layer.
Drizzle with half the oil and generously season with salt and black pepper.
Roast for 15 minutes.
Meanwhile, bring a medium pot of water to a boil.
Generously salt the water once boiling then drop in the pasta.
Cook for 6-7 minutes or until al dente.
As the pasta is cooking, add the remaining tablespoon of oil to a medium skillet and heat over medium.
Sauté the onion and garlic until softened and fragrant.
Drain the pasta and add it to the skillet with sautéed onion and garlic.
Add the roasted tomatoes followed by the spinach. Toss.
Season to taste with salt and black pepper. Toss again
Finish with grated parmesan, if desired and a drizzle of olive oil.
Plate and serve.