
Don't get me wrong; I never, ever got to have fluff as a child. For good reason, now I know what goes in it: it must be a dentist's worst nightmare. But I had bread, and I had peanut butter, and... Mmmm. Actually, I can't relate this without a fluffernutter sandwich. I'll be right back.
Mmmmmm. See, this is another reason to make fluff seldom and sparingly. Because this happens -- it's delicious, and you want to eat it. If I had kids, I'd probably make this once a year, maybe in February during school vacation -- you know, something to tide them over in those cruel candyless months between Christmas and Easter. I'd also make them help make it, because DAMN, the amount of sugar in this will establish for them exactly why this is a once-a-year treat.
Okay! Now that the health warning's out of the way, here we go.
I used Eileen Talanian's "Marshmallows" book, which looks like it belongs on Amy Sedaris's

...unless you're making fluff, in which case measure out 1.25 cups of the syrup and put into a saucepan with half a cup of water and another 1.5 cups of granulated sugar. Same as with the syrup, mix the ingredients, bring to a boil, cover and sweat the saucepan for 2 minutes, and then chuck in the candy thermometer.
Separate four eggs, putting the whites in your trusty Kitchenaid and saving the yolks for some

At the 220 mark, start the egg whites in the Kitchenaid and whisk on medium until it's thick and fluffy. Has the boiling sugar stuff reached 240? Good! Remove from heat, remove candy thermometer, and be VERY CAREFUL. The base is all gooey and sticky and also 240 degrees hot, so obviously this is a bad time to have it come in contact with your skin. Tip the base into the mixer while the whisk's going, but don't pour it onto the whisk, pour it along the side of the bowl -- aim for a point above the top level of the egg whites.
Once everything's in, crank the mixer up to high for 7 minutes -- this is also the time to add 2

I did that with most of the fluff, saving aside a little to put on my fresh bread with peanut butter, and also holding aside about 2 cups at the end when I dashed a tiny bit of mint extract into the mixer and made minty fluff for topping my cocoa. Mmmmm. Looks delicious there, and is delicious now.
The original Marshmallow Syrup recipe is actually double what I've posted above, but considering I just made an actual quart of fluff off of halving it, I think that most people wouldn't need the full dose of Syrup. And of course, I'd be remiss not to point out that this batch of fluff has no oil or anything naughty like that, but certainly DOES have almost FOUR CUPS OF SUGAR. Yikes.
So, what I've learned about fluff: Like most things that are bad for me, I love it. My mother was right not to give it to me in elementary school, though if I'd seen how much sugar went into it I might've been more reasonable about that rule. I would make this very seasonally, as in "for February school vacation" or "for a sundae-making event". And I'd make my consumer watch, so they know exactly what they're getting into.
To the kitchen!