Just like your favorite treats growing up, but made in a way that will make you feel *very* fancy. The classic rice krispie crunch, the stickiness of the marshmallows, and a nutty depth from the brown butter will make these the hit of any party!
Combine gelatin and ¼ cup of water in the bowl of a stand mixer fitted with the whisk attachment. Mix together then let stand.
Heat corn syrup, sugar, ½ cup water, and salt in a saucepan over medium-high heat. Without mixing, bring the mixture up to 240 degrees (about 10 minutes). Once at 240°F, immediately remove the sugar mixture from the stovetop.
Turn on your stand mixture on low, beginning to break up the gelatin mixture that has formed.
With the mixer still on low, slowly pour the sugar mixture into the stand mixer bowl. Once you've incorporated the full mixture, turn the mixer to medium-high. About 3-5 minutes later, the mixture will have approximately doubled in size, and be white and fluffy. Turn off the mixer. Congrats- you've just made marshmallows!
Make the Brown Butter.
Place the butter in a saucepan over medium heat. Stirring occasionally, keep the butter on the stovetop while it hisses and pops.
After a few minutes, the mixture will start to rapidly bubble up. Shortly after, you'll start to see some brown bubbles that stand out in the sea of buttery yellow. This is when you know you're done! Remove from the heat, and stir to disseminate the yummy brown flecks.
Wait a few minutes for it to cool slightly, then pour the brown butter mixture (brown flecks and all) into the stand mixer with the marshmallow fluff. Add vanilla. Whisk until fully combined, which may take a minute or two.
Make the Rice Krispies.
Stir the 8 cups of rice krispie cereal into the marshmallow fluff until evenly distributed.
Grease a 9x13 pan, and put the marshmallow mixture into the pan. Spread until evenly distributed.