Patriotic JellO Marshmallows Layered Red White and Blue Showstopper

Instructions:

1. Prepare the Pan: Grease a 9x13 inch pan generously. Line with parchment paper, leaving an overhang on the long sides, and grease the parchment paper again. Whisk together the powdered sugar and cornstarch, then dust the prepared pan thoroughly, knocking out the excess mix.
2. Bloom the Gelatin: In the stand mixer bowl, pour 1 cup of cold water over the unflavored gelatin powder. Stir gently and let stand for 10 minutes until it is spongy (bloomed).
3. Make the Syrup: Combine the granulated sugar, 1/2 cup cold water, corn syrup, and salt in a heavy-bottomed saucepan. Stir briefly to dissolve the sugar on the bottom.
4. Boil and Hit Temperature: Bring the mixture to a boil over medium-high heat. Do not stir after boiling begins. Insert the candy thermometer and boil until the syrup reaches precisely 240°F (115°C). Remove immediately from heat.
5. Whip the Syrup: With the mixer on low speed, slowly and carefully stream the hot sugar syrup into the bloomed gelatin mixture. Avoid hitting the whisk or the sides of the bowl.
6. Whip to Stiff Peaks: Increase the mixer speed to high. Whip continuously for 10–12 minutes until the mixture triples in volume, turns brilliant white, and becomes thick, glossy, and pulls away from the sides.
7. Divide and Color: Reduce mixer speed to low for 10 seconds. Divide the whipped marshmallow base evenly into three separate, lightly oiled mixing bowls. Quickly fold the 3 tablespoons of blue Jell-O powder into the first bowl and the 3 tablespoons of red Jell-O powder into the second bowl. Stir vanilla extract into the third (white) bowl.
8. Layer 1 (Blue): Scoop the entire blue mixture into the prepared pan. Smooth gently and quickly with an oiled spatula.
9. Layer 2 (White): Immediately and gently spread the white mixture evenly over the blue layer, taking care not to press down hard.
10. Layer 3 (Red): Spread the red mixture over the white layer. Smooth the top surface as much as possible.
11. Set: Leave uncovered at room temperature for 30 minutes, then transfer to the refrigerator to chill for at least 4 hours, or ideally, overnight.
12. Cut and Coat: Use the parchment paper overhang to lift the entire marshmallow block out of the pan onto a cutting board dusted heavily with the powdered sugar/cornstarch mix. Oil a long, sharp knife frequently. Trim edges and cut the block into 1-inch squares. Toss the cut marshmallows gently in the remaining dusting mixture until fully coated. Store in an airtight container.