Cook the dried spaghetti in salted water and cook until al dente according to the package directions. Drain transfer to a bowl. Set aside and toss with a little oil to prevent sticking.
In a big pan, heat olive oil in a medium pan over medium heat. Stir in mushrooms and cook until they turn brown and softened.
Pour in the sauce and cook until it boils. Season with salt and pepper if necessary. Toss in the cooked spaghetti. Turn off the heat.
Divide the pasta into serving plates and garnish with sliced basil leaves. Serve immediately.