Method

• 01
  Spray a 9x9-inch pan with nonstick cooking spray. Place the cranberries and 1/2 cup of water in a small saucepan. Heat them together over medium heat until the cranberries pop and the mixture becomes thick about 10 minutes.
• 02
  Transfer the cranberries to a food processor or blender and blend them until smooth. If the cranberry puree seems very thick, add 1-2 tbsp of water to it while you blend to thin it out a bit. Press the puree through a fine wire-mesh strainer to remove the bits of skin.
• 03
  Measure out 1/2 cup of cranberry puree. If you have more, save it for another use, and if you're a little short, add enough water to equal 1/2 cup.
• 04
  Transfer the 1/2 cup of cranberry puree to the bowl of a large stand mixer. Start whisking the puree gently with a small whisk or fork, and while you're whisking, gently sprinkle the powdered gelatin on top. Set the mixing bowl aside while you prepare the sugar syrup.
• 05
  Combine the remaining 1/2 cup of water, corn syrup, granulated sugar, and salt in a medium saucepan over medium heat. While it heats, stir frequently and brush down the sides of the pan with a wet pastry brush.
• 06
  Once the mixture comes to a boil, insert a candy thermometer and stop stirring. Cook the sugar syrup to 245℉. Once at 245℉, remove the pan from the heat and take out the thermometer.
• 07
  Place the mixing bowl with the cranberry/gelatin mixture in the mixer and start beating it on slow speed with the whisk attachment. While the mixer runs, slowly stream in the hot sugar syrup.
• 08
  Once all of the syrup is added, gradually increase the speed to medium-high and whip for 5-7 minutes, until the marshmallow is very shiny and thick, and when you stop the mixer and lift the whisk, it falls from the whisk in a very slow, thick ribbon.
• 09
  Scrape the marshmallow into the prepared pan and smooth it into an even layer. Let it sit and firm up at room temperature for at least 6 hours, or overnight.
• 10
  Sift the powdered sugar with the corn starch. Sprinkle the sugar/starch mixture on top of the marshmallow, and all over your work surface. Flip the marshmallow out of the pan, sprinkle more sugar on top and cut the marshmallow slab into small 1-inch squares with a knife or pizza wheel.
• 11
  Toss the marshmallows in the sugar mixture to keep them from sticking together. Store Cranberry Marshmallows in an airtight container at room temperature for up to two weeks.