1 1/2 ounces gelatin
11 ounces champagne
11 ounces corn syrup
16 ounces champagne
28 ounces sugar
1/2 tsp kosher salt
optional: 1 vanilla bean, seeds scraped and pod reserved for another use
optional: 1/4 tsp rose flower water
ample powdered sugar for dusting
Have a lightly greased 9â€x13â€ pan at the ready.
Combine the gelatin and 11 ounces of champagne together in the bottom of a stand mixer bowl. Set aside.
Pour sixteen ounces of champagne into a medium pot and place over medium-low heat. Simmer until the mixture is reduced by half, about 15 minutes. The actual time it takes depends on the width of your pot and specific heat, so keep an eye on it as it may go faster than expected. Weigh the champagne after reducing to make sure youâ€™ve taken it down to eight ounces. If you accidentally reduce it too far, add a little more champagne to bring it back to eight ounces.
In the same pot, combine the eight ounces of champagne reduction with corn syrup, sugar, salt, and vanilla bean scrapings. Set over medium heat and stir gently, taking care to not splash liquid up the sides of the pot.
Keep cooking, undisturbed, until the mixture registers 240Â° on a candy thermometer. Once it does, shut off the heat and let it stand until it cools to 210Â°. This is important; too hot a mixture will prevent the gelatin from setting properly, leaving you with unworkable, gooey â€˜mallows in the end.
Once the mixture has cooled to 210Â°, pour all of it into the mixing bowl with the awaiting gelatin. Fit the bowl with the whisk attachment and whip on medium speed for about a minute, until the gelatin has fully melted. Now, crank it to medium-high and whip until the mixture has nearly tripled in volume.
When it has, shut off the mixer and set the whisk attachement aside (donâ€™t even bother to try and scrape it clean, the mess to reward ratio favors mess by far). Pour the marshmallow goo into the prepared pan and bang the pan against the counter a few times to level the mixture.
Dust the top of the giant marshmallow with some powdered sugar, cover in plastic and refrigerate at least 4 hours, but preferably overnight.
To cut the marshmallows, dust a cutting board with powdered sugar and have a large chefâ€™s knife ready. Take the pan of chilled marshmallows and literally reach your fingers between the â€˜mallow and the pan, and pull that guy right outta there.
Dust the exposed bottom of the â€˜mallow with more powdered sugar. You can use a metal cookie cutter to cut the marshmallows into shapes, or use a knife to cut out the pieces instead. For the latter, cut the big marshmallow pillow into 13, 1â€ strips. Stop periodically and clean the knife as gunky marshmallow buildup on the blade will give subsequent cuts a ragged edge. Once the strips are cut, roll them about in powdered sugar so none of the sides are sticky.
Now cut the strips in 1â€ increments (you can gather up 3 or 4 strips to chop up in one go).
Toss the cut pieces in powdered sugar to prevent sticking.
Store in an airtight container or zippy bag. Theyâ€™re essentially nothing but sugar, so they have a terrific shelf life. About two weeks at room temperature, a month in the fridge, or eternity in the freezer.