This cake looks really sweet but it's not. It's delicious.
ーThis cake is not that sweet and it's really good.
「このケーキ甘さ控えめですごく美味しいよ。」
not that sweet で「あまり甘くない」=「甘さ控えめ」と言えます。
ーThis cake looks really sweet but it's not. It's delicious.
「このケーキすごく甘そうだけど、そんなことなくてとても美味しいよ。」
looks really sweet で「すごく甘そう」
delicious で「とても美味しい」
ご参考まで!