Is baking a cake using ingredients found in the wild (like in minecraft) possible?

It would probably be possible u find coco u find wheat you get milk and eggs

Finding actual cake ingredients in the wild may be challenging. You probably will use the milk of whatever animal you can find. And once you find it you have to milk it. Oooh, yay, You're not going to come across a wheat field ready to be harvested unless you grew it yourself, which kind of misses the point of it being the wild. And I don't think cows and chickens roam the vine covered flats.

So theoretically, sure. Logistically, not likely

Have you ever eaten a delicious Hickory Nut Cake? It's a whole lot of work to crack all those hickory nuts, but they are very tasty.

Sure but it is a complicated process.
You would have to find grain then grind it.
Gather eggs, almost any egg would work if they are small you would need more.
A sweetener so honey would probably be the first choice unless you lived in an area where sugar cane grows.
As civilizations developed you would have people that grew the grains and people that would grind the grain and possibly a trade would be made. The person that grew the grain would give a portion of his harvest to the miller who would sell it and the farmer would take a portion home for use for the year and the miller may not charge him for grinding the grain.

The complexity of one person having all the necessary ingredients for a cake made cakes and other baked goods an involved and expensive process. That is why many times cakes were only for very special occasions. Things like fruit cakes were more common as they use less four and less sugar and dried fruits and nuts were much easier to come by.
Molasses was a much more common sweetener as was honey.

No. You're not going to get flour or sugar to the right fine grained texture without commercial processing.