• Before starting, preheat the broiler to high.
• Wash and dry all produce.
• Bring a large pot of salted water to a boil over high.
• To the boiling water, add penne. Cook for 12-14 min, until tender but still firm to the bite.
• Strain penne, then return to the pot, off heat.

• Meanwhile, peel, then cut shallot into 1/4-inch pieces.
• Peel, then mince or grate garlic.
• Roughly chop spinach.
• Drain, then rinse olives. Pat dry with paper towels, then roughly chop.
• Pat bocconcini dry with paper towels. Tear into quarters, then season with 1/4 tsp (1/2 tsp) garlic salt and pepper.

• While penne cooks, heat a large oven-proof pan over medium.
• When hot, add 1 tbsp (2 tbsp) oil, then sausage, shallots and garlic. 
• Season with salt. Cook for 4-6 min, breaking up sausage and stirring often, until sallots have softened, and sausage is cooked through.**

• To the pan with shallots, add crushed tomatoes, olives, 1/4 tsp (1/2 tsp) chili flakes and 1/4 cup (1/2 cup) water. (Like things spicy? Add more chili flakes!)
• Cook for 4-5 min, stirring occasionally, until sauce thickens slightly.
• Remove from heat.
• Stir in 1 tbsp (2 tbsp) balsamic glaze.
• Season with 1/4 tsp (1/2 tsp) garlic salt and pepper.

• To the pot with penne, add sauce and spinach, then stir to combine.
• Transfer penne to the same oven-proof pan. (NOTE: If you don't have an oven-proof pan, transfer penne to an 8x8-inch [9x13-inch] baking dish.)
• Arrange bocconcini over penne. Sprinkle Parmesan over top.
• Broil in the middle of the oven for 4-5 min, until cheese melts.

• Divide penne al forno between plates.
• Sprinkle any remaining chili flakes over top, if you like.
• Drizzle with remaining balsamic glaze.

If you've opted to add sausage, add sausage along with shallots and garlic. Season with salt. Cook for 4-6 min, breaking up sausage and stirring often, until sallots have softened, and sausage is cooked through.**