平片式蛋糕a sponge cake (= a light cake made from flour, butter, eggs, and sugar) that is baked in a rectangular tin
The sheet cake was adorned in blue and red icing. 平片式蛋糕上装饰着蓝色和红色的糖衣。
He brought a chocolate sheet cake into the office for his birthday. 他过生日的时候带了一个巧克力平片式蛋糕去办公室。