ZBVau2EpUDJJqT0eElFbix5KFKpRIYw2rKj3dm10UR0tCn4hPuFhGP8wTd0gCL4tPu4vRqsUvwemzlEczedzIT4mYWMvIO4iYzFiMO4zVA4hBqVvZV4gMO4uLu4vYz0yVG4fNP0sYI0oGi4lBP8kXj4uUR0hZH0hPE0nVES0YOZgPfSdmD4g

Note: You do not need information other than this question. You do not need information from the source code / edit history. This note is not a part of the puzzle nor is it a hint.

Hint:

The title is the key.

• If you put Vinegèr on a Caesar salad, it isn't a Caesar salad anymore, just a Vinegèr salad with different key ingredients.
– Bass
Feb 2 at 16:21
• Well, technically yes, but then its more like a Vineger salad with the key ingredient of a Caesar salad? Feb 2 at 16:23

The title hints that Caesar cipher and a Vigenere cipher are involved and that the title itself is a Vigenere key, and the set of characters present in the text suggests that Base64 is involved. Trying the obvious guess using this Cyberchef recipe produces apparent nonsense, except for the Decode at the beginning.
Now, the intended solution is to use the Vigenere key VINEGARZONZCAESARZSALAD and then obey the directions in the deciphered text, but let's see what it takes to discover that key without just guessing that spaces are replaced by Zs. Here is another CyberChef recipe which performs Vigenere key-dragging, by splitting the ciphertext into blocks of 8 letters, and subtracting the key VINEGAR from each block separately before decoding the result with Base64. Blocks of 8 letters are chosen because Base64 operates on blocks of four letters, and if two such blocks in a row are deciphered convincingly then we can be fairly sure that VINEGAR was the key used for those blocks.
Note the line with .- -. , an obvious snippet of Morse Code which is unlikely to appear on accident. This indicates the key fragment VINEGAR is at least repeating. If VINEGAR appears multiple times in the key, but the given key does not decipher the text, maybe the true repeated key is longer than the given key. Add letters to the end of the key one by one until this recipe gives many fragments of Morse Code and also the string a bas which might be a piece of legible text.
The number of letters added is three, which is one less than the number of words in the given key. Rearrange the key into VINEGARAONACAESARASALAD to get a mostly-deciphered text.