Strawberry mousse with pistache cream inside, the Saya by Sadaharu Aoki is my favourite cake. Sadaharu Aoki have two patisseries in Paris, 35 Rue de Vaugirard near the Luxembourg park, and 56 Boulevard de Port Royal in the 5 arrondissement.
I've interviewed curator and founder Marie Madec a couple of times now; she represents their contemporary artists with a dedication and enthusiasm that's infectious.