acheter un gâteau
Gateau is food cake in french
A birthday cake in French is 'un gâteau d'anniversaire'
gâteau
A banana cake is "un gâteau à la banane" in French.
gâteau sucré
I buy in french is J'achete
In French, you would say, "Puis-je avoir un gâteau, s'il vous plaît ?" This phrase translates directly to "Can I have a cake, please?" in English. It’s a polite way to request a cake in French-speaking contexts.
If you mean a slice of cake it is - tranche
gâteau basque.
to buy is translated 'acheter' in French
Gateau à la fraise
"un gâteau parfait"