Butter and lightly toast the Hawaiian rolls in a skillet before assembling to prevent sogginess and add a subtle golden flavor that complements the marinara sauce.

Soak your breadcrumbs in whole milk rather than water before mixing into the meatball mixture—this creates an incredibly tender, juicy texture that stays moist even when simmered.

Mix grated Parmesan directly into your meatball mixture before cooking, not just as a topping—this distributes umami flavor throughout and prevents the cheese from becoming chalky.

Add meatballs to marinara sauce and simmer for 15-20 minutes instead of just heating through—this allows the sauce to infuse into the meatballs and develop deeper, richer flavors.

Layer mozzarella on the bottom half of the roll before adding the meatball, then broil just until melted—this prevents the cheese from sliding off and ensures it adheres to the bread.