A maple bar has been a vape I've mess around with off and on for about a year now, and now I finally found it.
For background, as a weight class athlete and bodybuilder I generally keep a very strict diet, but I'm also a former fat kid so I LOVE food and Maple donuts have always been one of my favorite foods to eat, so since I partially use vaping to curb my sweet tooth, this was not just a flavor I wanted, but somewhat needed for my own sanity. Now I can have a little cheat day ever day. :)

FLV Maple bar:
So this is obvious, it's a maple donut. But it's not quite a maple donut. Check out ConcreteRiver's review on the DIY subreddit, I'd agree with him. But the short of it is it's dry, somewhat stale donut base, but the Maple frosting is very good, and it's just that, a maple/vanilla frosting, not maple syrup.
FA Zeppola:
The perfect donut body, light and fluffy, somewhat fried and sugar covered. This simply fills the body of the donut base out. The only issue with it is it's a little TO light of a donut in my opinion so next we add
TFA Cinnamon danish:
Okay, so this is SUPER low %, but to me all the Cinnamon danish's are very strong. I prefer TFA over CAPS, the cinnamon is more baked into a dense dough and less "bright" so to speak. .25% is low enough it doesn't provide any cinnamon flavor to the finished recipe, but it adds just a bit of dense dough to the donut.
FLV Frosting:
I actually really love this flavor, it's kinda waxy but in a good way. Not like a buttercream frosting, but like canned vanilla frosting from the store, which works great to separate the maple frosting from the dough flavors making it seem more like it's on top of the donut and not just maple baked dough
FA Maple Syrup:
The frosting kinda lightens the maple frosting and brings a touch to much vanilla, so this just brings the vanilla back into balance.
FLV Milk & Honey:
This is a weird flavor. But it's also an amazing flavor that I only just recently finally picked up. It's not honey, but it's not maple either. It's a weird somewhat dark sweetness, but when combined with other maple flavors it really takes on a darker, more maple type flavor. Without this the whole thing was just a little, so this smooths it out, sweeten's things up, and enhances the maple frosting. I would say this isn't 100% needed, but it's much better with than without.
Super sweet:
This is always optional, but it's a donut and donuts have all the sugar in them, so just put it in.

Right after I mixed this it smelled dead on like a maple donut and tasted great after a shake, so you can SnV this, but it really comes together better after a week, letting some of the dough flavors settle in, and the frosting/cream type flavors fill out.