Layer-Cake Desert

Layer Cake Desert is the desert world in New Super Mario Bros. U, lying directly north of Acorn Plains, north-west of Sparkling Waters and Soda Jungle and south-west from Frosted Glacier. As with previous World 2's in the series, it takes place in a desert, but unlike the previous desert worlds, it has various desserts within the world, such as giant cakes (with one giant cake in the world map) and giant melting ice cream cones. This is likely a pun on the similarity of the words "desert" and "dessert". The boss of this world is Morton Koopa Jr. There are also giant Moai statues in a sea of sand, which also appear in some levels and in the world map. A Super Acorn can also be found in the map alongside the Enemy Courses, where it'll possibly give Mario a Super Acorn in his inventory. At the end of Layer Cake Desert, there's a fork in the road that leads to Frosted Glacier or Sparkling Waters.

Levels

 * Layer Cake Desert 1: Stone-Eye Zone
 * Layer Cake Desert 2: Perilous Pokey Cave
 * Layer Cake Desert 3: Fire Snake Cavern
 * Layer Cake Desert Fortress: Layer Cake Fortress
 * Layer Cake Desert 4: Spike’s Spouting Sand
 * Layer Cake Desert 5: not available yet
 * Layer Cake Desert 6: Blooming Lakitu’s
 * Layer Cake Desert Castle: Morton’s Compactor Castle

Trivia

 * Every world (counting this one) in New Super Mario Bros. U that is confirmed and is showed, has a pipe at the beginning of the world.