Step 6: Marshmallow Layer: Preparation
I should state right now that there are two different methods I used to apply a marshmallow surface. One is frustrating, one is not. Your choice should be made based on how much you like to be sticky.
The more frustrating option is to whip your marshmallows until light and fluffy, but not so much that the mixture starts to cool and thicken. While still relatively thin, pour the whole kit and kaboodle over the stacked cracker and brownie, and allow the marshmallow to drip off. This will provide a thin and uniform coating. The downside, of course, is that the marshmallow will set*, and you'll have to scrape the individual treats off with a hot knife.
The less frustrating option would be to pipe the marshmallow on top of the brownie. This has some aesthetic advantages, but then you can't really call the treats "marshmallow-covered," which means you get assessed -100 pastry street cred points.
Both batches follow the same basic recipe. This makes waaaaay too much marshmallow for the "piped" option, so make sure you have a vessel prepared to hold the overflow.
Measure the following directly into a medium-sized saucepan:
340 grams sugar
225 grams corn syrup
55 grams mild honey
85 grams water
Measure these out separately:
20 grams gelatin (three packets of the Knox unflavored, if you're using that)
115 grams water
10 grams vanilla extract
*enough to be hard to release from the rack, not so much that it isn't maddeningly sticky