Sky-High Sundae

Sky-High Sundae is a course released as part of Wave 2 in the Booster Course Pass in Mario Kart 8 Deluxe and set to be released a later date in Mario Kart Tour. It is the fourth and final course of the Propeller Cup in Mario Kart 8 Deluxe and is currently the only new course in the Booster Course Pass. It is set entirely in anti-gravity (the fourth course to have this trait after Mute City,, and Big Blue) in a large area (described as a city by its French name) made entirely of ice cream and other candy-related food high in the sky. It is the first course that debuted in Mario Kart 8 Deluxe to later make an appearance in Mario Kart Tour, as well as the first in the series to be announced for two games simultaneously. Despite being the only new course added so far in the Booster Course Pass, it is not the only course to lack a prefix in the pass, as Ninja Hideaway also lacks a prefix.

Following the release of the first wave of the Booster Course Pass, a datamine revealed a banner featuring numerous unreleased courses. Among the courses was, four months before the course's official series debut.

Course layout
The track starts off in a bar or diner that is inside of a giant freezer, after which the racers use Glide Ramps to fly either into or around a giant ice cream cone. Flying into the hole in the cone rewards players with Item Boxes. After that, they land on a chocolate-covered cake with a giant H on it, resembling a helipad. Upon landing, they begin traveling down a light-blue staircase, and at the bottom the path begins curving to the left while proceeding to go up a staircase. At both staircases, there are railings which split the players. After the upward staircase, the player begins to ascend a slope which splits off into two paths. At the top of those paths, they begin jumping down onto some platforms, which can be landed on both above and below. After the two paths join back together, a path made out of giant ice cream cones circles around an even larger piece of ice cream inside a cup. After turning around, the player jumps between three giant pieces of ice, which lead to a giant ice tray that leads back into the giant freezer where the Finish Line is.

During the race, various advertisements can be seen on giant waffle pieces. At the staircase segment, there are numerous ice cream shops to the right of the path. In the sky, a helicopter modeled after an ice cream cone can be seen, complimenting the helipad cake seen at the beginning.