It's called 'The Latteria' and they serve pizza, ice cream, wraps and sandwiches. 'Latteria' refers to the origin of this historical building as in the 19c it kept cows of which the milk was used for the zoo's animals, staff and visitors.
It's one out of three good indoor dining places, together with the Grand Café Flamingo (vingerfood, belgian beers, coffee & tea) and the Savanna restaurant (main restaurant).