(45 minutes + cooling time, makes about 50)
3 packages unflavored gelatin
1/2 cup water
1/2 c. soursop puree (from frozen is fine)
1 1/2 cups granulated sugar
1 cup light corn syrup
1/4 teaspoon salt
powdered (confectioner’s) sugar
butter (for greasing the pan)
blueberry simple syrup for marbling:
– 1 c. blueberries
– 1/2 c. granulated sugar
– 1/2 c. water
1. Empty gelatin packets into bowl of stand mixer (whisk attachment), with soursop puree. Stir briefly to combine.
2. In a small saucepan (a bigger one will be heavy and hard to hold steadily at a later stage) combine water, granulated sugar, corn syrup, and salt. Cover and cook over medium high heat for 4 minutes. Uncover and cook until the mixture reaches soft ball stage (240 degrees if you have a candy thermometer), approximately 8 minutes. Once the mixture reaches this temperature, immediately remove from heat; if it continues, it will swiftly turn into hard candy.
3. Turn mixer on low speed and, while running, slowly pour the sugar syrup down the side of the bowl into the gelatin mixture. (Be very careful with the sugar syrup, as it is scaldingly hot and will burn you badly if it gets on your skin.) Once you’ve added all of the syrup, increase the speed to high.
4. Continue to whip until the mixture becomes very thick and is lukewarm, approximately 12 minutes.
5. While it’s whipping, make simple syrup. Bring 1 c. blueberries, 1/2 c. granulated sugar, and 1/2 c. water to a boil. Boil for 10 minutes, stirring, then pour through a sieve. You’ll only need a few teaspoons of syrup; the rest of the berry mixture and syrup can be reserved for adding to yogurt, ice cream, spreading on toast, etc.
6. Butter a large 9 x 12 pan and dust with powdered sugar. Prepare an oiled spatula.
7. Pour the marshmallow mixture into the prepared pan, spreading it evenly (and swiftly) with an oiled spatula. Add a few drops of blueberry syrup scattered across the top and drag a knife through the marshmallow, lengthwise and crosswise, to create a marbled effect.
8. Dust the top with enough of the remaining powdered sugar to lightly cover. Reserve the rest for later. Allow the marshmallows to sit uncovered for at least 4 hours and up to overnight.
9. Turn onto a board, cut into squares and dust all sides of each marshmallow with the remaining powdered sugar, using additional if necessary. May be stored in an airtight container for up to 3 weeks, or frozen.