1. Line a baking sheet with parchment or wax paper and coat lightly with vegetable oil spray. Set aside.
2. Combine gelatin and six tbsps water in a mixing bowl. Place bowl on a mixer fitted with a whisk attachment.
3. In a medium saucepan, combine sugar, corn syrup, and ¼ cup water; mix until there are no dry spots, and use a pastry brush to push down any sugar crystals from the sides of the pan.
4. Clip your candy thermometer to the side of the pan and cook the mixture over high heat until it registers precisely 240 degrees Fahrenheit. Remove from heat immediately.
5. With the mixer running on medium speed, slowly pour the hot sugar down the side of the bowl. Add the salt. Increase the speed to medium high and beat for five minutes or until the mixture springs back from the sides of the bowl but is still warm to the touch.
6. Add the vanilla and other flavorings and beat briefly.
7. Scrape the marshmallow onto the prepared pan, spray the top with vegetable oil, and cover with an additional sheet of parchment or wax paper.
8. With another pan, or a rolling pin, gently flatten the marshmallow to an even 1" thickness.
9. Let it set overnight, then use a clean pair of scissors to cut the marshmallow into 1" squares. To keep the candies from sticking together, toss them in a mixture of equal parts cornstarch and powdered sugar. Store in an airtight container until ready to eat.

1. Prepare an 11" x 7" pan with at least 1" sides with a light coating of vegetable oil or spray, and set aside.
2. In a heavy-bottomed saucepan, combine sugar and corn syrup; mix until there are no dry spots, and use a pastry brush to push down any sugar crystals from the sides of the pan.
3. Cook the mixture over high heat until it starts to turn golden. Immediately whisk in butter, one tablespoon at a time. Gradually pour in cream, a few tablespoons at a time, whisking thoroughly after each addition.
4. Clip the candy thermometer to the side of the pan and cook, stirring continuously, until the mixture reaches precisely 248 degrees Fahrenheit.
5. Remove from heat and whisk in salt and vanilla.
6. Pour caramel into prepared pan and let sit for several hours or overnight.
7. Turn the sheet of caramel onto a cutting board and refrigerate for 15 minutes.
8. With a knife or rotary cutter, cut the caramel into 1" square pieces, and individually wrap them in parchment or wax paper.