While I am supportive of Ukraine's efforts to curb Russia's weapons production, I'm a tad confused by this video.

Initially we see a single-prop 2 person aircraft with landing gear down crash into a building and an explosion ensues.

Later in the video we see a still of a winged drone as the video informs us that Ukraine have been improving their drone fleet, obviously a fraction of the size of the aircraft we see in the crash.

Any possibility that someone has taken footage of a plane crash and spun a yarn from it? Or is there another explanation why the aircraft featured at the start of this video is nothing like the drones Ukraine have been using against Russian ships and other targets?

I understand the confusion, but as I understand it this “drone” was a single engine plane (172?) modified for use as a drone. I don’t know what kind of drone hit the refinery at the same time, but since it was in the same town 1200 km from Ukraine it’s likely they used the same civilian aircraft “drone” for that simultaneous attack.
The news about the battlefield drone advancement in the same clip did confuse the details about this extremely long range drone attack deep in Russia.

I've seen some additional reports now with verified details from the BBC and Reuters - and a proper landscape view of the impact - none of that side panel blurring business! Both news outlets confirm what you've said, converted light aircraft, and they also state that Ukraine forces have taken responsibility for the attack. I'm still amused that they rigged it for remote control and left the landing gear down the whole way!

That particular aircraft doesn't have retractable landing gear.

Most small, single-engine aircraft do not have retractable landing gear.