This blog is to explain a bit about Cookie Run's cosmology. Note that game mechanics are canon, as several Cookies have made notice of them and are integral to the part of some characters' backstories, such as Angel Cookie's as well as them making up a large part of the tutorial level, which is also canon. Other inclusions of game mechanics in the story are the Bear Jellies, who were merely a way to increase score in OvenBreak, but became fully-fledged characters in Kingdom, as well as the Grand Champion's League where Gingerbrave and Purple Yam Cookie canonically participated in and won, with the Grand Champions League being a bracket-style tournament where the Cookie that earns the most score out of the other 3 competitors, wins. Cookie Rumble is also a score-based event, where Milk Cookie recalls participating in. Way of the Cookie is yet another score-based event, with cutscenes showing the opponents the player had to overcome in order to proceed. Several Cookies, such as Tiger Lily Cookie and Cream Puff Cookie, acknowledge the Temple of the Sky, which is the replacement of the Grand Champions League.
Dimension, Universe, Oven, Timeline, World and Tray are interchangeable as seen here, here, here and here. The Afternoon Tea Set theory is proven to exist through the Sugar Swan, who is one of the "wielders of cosmic power", the Trays shown in Tower of Sweet Chaos as well as being outright stated to exist in Devil Cookie's description. This would make Bonus Time (also known as Heaven) and every variation of it also a Tray.
Cookie Run currently has 4 main multiverses. OvenBreak, CookieWars, Kingdom and Puzzle World. Cookies from different verses generally have the same power and motivation as their OvenBreak counterparts, as Dark Enchantress Cookie in OvenBreak retains her desire to overthrow the witches and create the perfect Cookie (Eternal Night, Matcha Cookie) as she did in Kingdom as White Lily Cookie, and retains her abilities from Kingdom (Ravenous Slicer and Cake Witches) in OvenBreak. Scaling Cookies between their counterparts from OvenBreak, CookieWars, Kingdom and Puzzle World should be okay, since they would have the same potential as their alternate selves and the events that would cause a Cookie to cross-scale to another Cookieverse would just scale the Cookie to their counterpart in their respective Cookieverse.
The Middle Tray (also known as the Cookie World, This Universe and This Dimension) is constantly referred to as a universe, and the lower trays of existence are filled with an innumerable amount of Ovens. It is also shown that there are a countless amount of infinitely-expanding timelines due to the fact that changing the past doesn't change the future, instead making a new timeline. For each Oven, there is at least one Cake Tower within, which houses 150 Trays each.
The Witches created the multiverses in every iteration they've been seen in (Except for Kingdom, where The Sugar Swan created it) and Dark Enchantress Cookie surpassed them, making her and everyone who scales to her at least 2-B.