Whisk together the cornstarch and confectioners' sugar in a bowl. Grease an 8-inch square baking pan with cooking spray and dust with the cornstarch mixture. Set aside. Reserve the remaining cornstarch mixture.
Puree the strawberries in a blender until very smooth. Strain into a medium saucepan and add the granulated sugar and corn syrup. Bring to a boil over medium-high heat, stirring until the sugar is completely dissolved. Attach a candy thermometer to the pan and continue to boil until the temperature reaches 240 degrees F.
Stir together the gelatin and 1/2 cup cold water in the bowl of a stand mixer fitted with a whisk attachment.
Turn the mixer to low and carefully pour the warm syrup into the gelatin. When you have added all of the syrup, turn the mixer to high and beat until the mixture is very thick and holds stiff peaks, about 15 minutes. Add enough food coloring to turn the marshmallow a pale pink, 3 or 4 drops.
Coat a rubber spatula with cooking spray and scrape the marshmallow into the prepared baking pan. Grease your fingers and gently press the mixture into the pan, smoothing the surface. Dust with the cornstarch mixture, reserving the remaining for removing the marshmallow. Let the marshmallow dry out at least 4 hours and up to overnight.
Sift some more of the cornstarch mixture onto a work surface and turn the marshmallow out onto it. Dust the top. Use a sharp knife to cut the marshmallow into approximately 1 1/4-inch squares, cleaning the knife as necessary between cuts. Dust the squares with more of the cornstarch mixture to coat.
Line a baking sheet with parchment paper and lightly grease the paper with cooking spray.
Combine the chocolate chips and coconut oil in a small microwave-safe bowl. Microwave in 30-second intervals, stirring between each, until melted, about 2 minutes.
Working one at a time, make sure each marshmallow is evenly coated in the cornstarch mixture but there are no big clumps on the surface. Dip about one-third of the marshmallow into the chocolate and put it on the prepared baking sheet. Sprinkle the top with sprinkles. Repeat with the remaining marshmallows. Freeze or refrigerate the marshmallows until set, about 5 minutes. Store at room temperature up to 2 days.
Copyright 2018 Television Food Network, G.P. All rights reserved.