1/2 cup cornstarch
1/2 cup confectioners' sugar
3 envelopes unflavored gelatin, such as Knox
2/3 cup + 1/3 cup cold water, divided
2 cups sugar
1/2 cup light corn syrup
3 large egg whites, at room temperature
1/4 teaspoon salt
2 teaspoons mint extract
6 drops green food coloring, optional
1 1/4 cups dark chocolate chips
- Lightly brush a Farberware® 9 by 13-inch nonstick baking pan with oil.
- Combine the cornstarch and confectioners’ sugar in a bowl and transfer to a wire mesh sieve. Shake the sieve over the pan to evenly coat it with the mixture. Reserve any leftover cornstarch mixture. (see step #7)
- Sprinkle the gelatin over 2/3 cup of the cold water in a bowl and let it stand to soften. Mix the sugar, corn syrup and remaining 1/3 cup water in a Farberware® 2-quart saucepan fitted with a candy thermometer and bring to a boil over medium-high heat.
- Meanwhile, combine the egg whites and salt in the bowl of an electric mixer and beat with the whisk attachment on medium until frothy. When the sugar mixture on the stove reaches 220°F, increase the mixer speed to high and beat until eggs hold stiff peaks.
- When the syrup reaches 240°F-245°F, slowly pour the sugar syrup into the egg whites, with the mixer still on high speed. Transfer the gelatin mixture to the now-empty warm saucepan, and stir until it dissolves. Slowly pour the liquefied gelatin into the egg whites. Add the mint extract and food coloring if using; continue to beat until the outside of the mixing bowl feels cool to the touch, 23-25 minutes. Add 1/2 cup of the chocolate chips and beat 30 seconds longer.
- Spread the marshmallow mixture evenly into the prepared pan and smooth the top. Sprinkle with the remaining 3/4 cup chocolate chops and let stand at room temperature at least 4 hours or overnight.
- Lightly brush a sharp knife with some oil then dust with some of the cornstarch mixture. Transfer the marshmallows to a cutting board and cut into 48 squares. Toss the cut marshmallows in a bowl with remaining cornstarch mixture; shake off excess. Store in an airtight container for 1-2 weeks.