Strawberry

From the Super Mario Wiki

The Strawberry is an ingredient to the strawberry cake that Princess Peach uses in attempt to satisfy Gourmet Guy's taste buds. Peach makes the cake after Mario rescues the Star Spirit from the Shy Guy's Toy Box. The Strawberry is the last item that Peach has to put in the cream, and she puts it after the cream is put on.

Adding more than one of these to the cake will result in Gourmet Guy spitting it out and Peach having to make the cake all over again.

Fruits

Apple | Banana | Bean Fruit | Berry | Black Apple | Blue Apple | Blue Banana | Blue Berry | Blue Watermelon | Bubble Berry | Cherry | Coconut | Crystal Berry | Dried Fruit | Durian | Giant Banana | Golden Apple | Grape | Green Banana | Green Watermelon | Heart Fruit | Keel Mango | Lemon | Lime | Mella Yella | Melon | Papaya | Peach | Peachy Peach | Pineapple | Pink Apple | Primordial Fruit | Red Apple | Red Berry | Red Watermelon | Star Fruit | Strawberry | Watermelon | Yellow Apple | Yellow Berry