The Escape Spark is the name given to the last shinespark in the game which skips a significant portion of the final escape sequence after defeating Mecha Ridley. You can set up the spark in several different ways, but once you've left the workbot room after setting it up you will only get one chance to attempt the spark itself because the door closes and locks behind you.
The quickest and hardest way to set up the spark is to perform a shinebreak by pressing down in a location where you break the speedblock in the floor in front of you without falling into the floor. This method is partially outdate by the next method which has a more consistent setup, but this method can be faster if you YOLO it without any time spent lining up with any visual cues.
If you look at the floor samus is standing on you'll see some dark vertical lines in the floor. The visual cue method is to line up samus's front foot so that it's between the first and second dark vertical lines, or at least making sure the back of her front foot is lined up with the front edge of the first line. With this lineup you will be able to run past the speedblocks and break the block behind you without falling into it. You still only have one tile of space left to press down and store the shinespark, but it's much more consistent and lenient than going for the first block without a visual cue. This method is only slower by the amount of time you spend lining up the visual cue.
If you break the floor and fail to store the spark, and if you pushed the workbot back far enough to the left, you have the option to run left to store a second spark and ballspark to the right to recharge it. This is slightly faster than running to the left, stopping, turning around and running back to the right.
Slower but Easy
If all else fails and you mess up all of the above methods, there is still the easy option to just break the floor and run back to get the spark normally.
The fastest way to get through the recharge room is to recharge once on the bottom floor, quickly jump all the way to the top and use a missile (or longbeam in 100%) to open the door and also break your spin so that you can spark into the final slope.
A safer method is to recharge on the penultimate floor and walk up to the door to initiate the ballspark.
Super Safe Recharge
You can also be super safe and charge on every floor if you need to. Each recharge costs extra time, but this is still faster than failing the spark entirely.
The ballspark is almost always preferable because it's consistent and the spaceboost saves less than a second if you do it right.