Why Scharnhorst is a battleship despite 11-inch guns

Were Scharnhorst and Gneisenau battleships or battlecruisers?

They were battleships by design and structure, even though they initially carried 11-inch guns.

Scharnhorst and Gneisenau count as battleships because of their design and structural intent. They were built when 11-inch weapons were the largest guns Germany had available for them. The design also allowed for a later move to 15-inch guns. Their initial battery is therefore a contemporary constraint rather than the defining feature of the type. Construction and intended role make them fast battleships rather than battlecruisers in this classification.