Heat a large skillet over medium-high heat and cook the ground beef for 4 minutes, breaking it into crumbles, until browned and cooked through to 160°F / 71°C.
Add the penne pasta, tomato sauce, beef broth, garlic powder, Italian seasoning, salt, and black pepper to the skillet and stir to combine.
Bring to a boil, then reduce heat to medium and simmer for 8 to 9 minutes, stirring occasionally, until the pasta is tender and the sauce has thickened.
Remove from heat and sprinkle the shredded mozzarella cheese over the top.
Cover the skillet for 1 minute to let the cheese melt, then serve immediately.