Complex sentence: Ovaltine has also been available in the form of chocolate bars, chocolate Easter eggs, parfait, cookies, and breakfast cereals, where it is only the brand name that connects the cereals with the chocolate drink.
Split into simpler sentences: Ovaltine has also been available in the form of chocolate bars, chocolate Easter eggs, parfait, cookies and breakfast cereals. In the last case it is only the brand name that connects the cereals with the chocolate drink.