Bring a large pot of lightly salted water to a boil. Cook spaghetti in the boiling water, stirring occasionally, until tender yet firm to the bite, about 12 minutes. Drain.

Meanwhile, heat olive oil in a skillet over medium-low heat and cook garlic until translucent and fragrant, about 2 minutes. Add cherry tomatoes. Increase heat, cook, and stir until lightly browned, 5 to 7 minutes. Season with salt and pepper.

Remove skillet from heat and mix in arugula. Mix in cooked spaghetti and drizzle with olive oil. Serve immediately with Parmesan cheese.