Is A Quarter Being Blank On One Side Possible ?

No, it is not possible for a coin to be struck only on one side. Just like you can't clap with only one hand, you need two dies to smash together with a blank piece of metal between them, in order for a coin to be made. If one of the dies is missing, then there's nothing for the other die to smash against, and no coin can be produced. You might end up with a "mint error", but it will look like a mangled mess, rather than a uniface coin.

An actual "uniface mint error" would require someone in the mint to deliberately make a blank die, and to install that blank die into the coinage press instead of a regular die. In other words, it would need a deliberate and premeditated act, and collusion from several people inside the mint, rather than a "mint error". Needless to say, nobody's going to go to all that trouble, just to make a bunch of quarters that end up in circulation somehow.

So, your coin originally started life as a normal two-sided coin, then had the reverse side deliberately removed. Some kind of buffing wheel, that leaves minimal trace, is the likely culprit. This is also why your coin weighs slightly less than a regular quarter.

to the CCF
Easy way to tell it has been removed is that there is no rim on the reverse,
you can't have a coin with the rim on only one side.

Yep
Removed reverse.

Not much chance it is an error coin but I'd keep it for a novelty.

Agree the most likely thing here is one side has been ground down, but what if two planchets had fed into the press on top of each other? Instead of yielding completely blank faces on the interior sides, would there be some design present, as with a capped die?

Two planchets getting fed into the machine directly on top of each other will also most likely create a mangled mess, as they both can't fit within the collar die. There's also going to be a lot more pressure applied to it, as the dies aren't going to be expecting the metal to be twice the thickness as normal. The two coins would likely mush together into one fused lump of metal, and since it wouldn't be ejected like a normal coin, would probably go on to become a "capped die" as further coin blanks are fed into the coin presses and struck while that lump of mangled metal is stuck there.

For older coins, running at lower pressures and slower speeds, it might have been more possible, but even then, the "blank side" wouldn't be perfectly flat; it would probably more resemble a "split planchet", with a rough and ragged surface, as the two coins would still need to be prised apart.

What you 100% wouldn't get is a coin somewhat resembling the OP's coin, with a perfectly normal obverse and edge but a "missing" reverse.

To form the rim on one side, would cause it to be formed on both sides of the coin. The reverse was sanded off. (thus the weight loss on the coin)