For a thinner sheet cake, a 3- x 3-inch serving is usually sufficient. For a thicker sheet cake, you’ll likely want to cut 2- x 2-inch or 2- x 3-inch pieces. Once you know the size of the slices, ...

The viral hack — the Instagram clip demonstrating this tutorial racked up nearly 34.9 million views — involves cutting the cake in half and carving 12 slices on each side. What’s so special ...