Lightly butter, or spray
with a non stick vegetable spray, the bottom of a 13x9x2-inch
pan. Line the bottom of the pan with parchment paper and sift three tablespoons of confectioners' sugar onto
the bottom of the pan (this will release the set marshmallow
from the paper).
Place 1/2 cup (120 ml)
cold water into the bowl of your electric mixer that is fitted with
a whisk attachment. Sprinkle the gelatin over the water and let stand
until gelatin softens, about 15 minutes. Meanwhile, in a heavy two quart
saucepan, place the sugar, corn syrup, salt, and remaining 1/2 cup
(120 ml) cold water. Stir over medium heat until sugar dissolves and
the mixture comes to a boil. Cover the saucepan with a lid and let
boil for about two minutes to allow any sugar crystals to dissolve
from the sides of the saucepan. Remove the lid and attach a
candy thermometer to the side of the pan. Increase heat to high and
boil, without stirring, until the syrup reaches 240 degrees F (115
degrees C), about 10 minutes.
Remove from heat.
With mixer running at
low speed, slowly pour the hot syrup into the gelatin mixture in a thin
stream down the side of the bowl. Gradually increase the speed to
high and beat until mixture has tripled in volume and is very thick
and stiff, about 10 minutes (looks like thick marshmallow cream).
Add vanilla extract and beat to combine, about 30 seconds longer.
mixture into the prepared pan and spread with a damp offset
spatula or rubber spatula. The mixture is very sticky so just smooth
it out as best as you can. Dust the top of the marshmallow with
tablespoons of confectioners' sugar and let stand, uncovered, at room
temperature until set, about 12 hours.
marshmallow from the pan by first running a small sharp knife
around the edge of the marshmallow to loosen it from the pan. Invert
the pan onto a large cutting board that has been dusted with
confectioners' sugar. You might have to use your fingers to help loosen
the marshmallow from the pan. Peel off the parchment paper (the
marshmallow will be sticky) and dust the top of the marshmallow with
confectioners' sugar. Cut
the marshmallow into squares using a pizza roller or sharp knife.
Dip the cut sides of the marshmallows in additional confectioners'
sugar. Shake off excess sugar and store the marshmallows in an
airtight container, at room temperature, for up to two weeks. Makes about 24 - 2
1/2 inch (7.5 cm) marshmallows.