Lightly grease an 8-inch square cake pan with canola oil.
In a medium heatproof bowl, mix the gelatin with 1/2 cup plus 2 tablespoons of cold water; let stand for 15 minutes.
Set the bowl over a saucepan of simmering water and cook, stirring occasionally, until the gelatin dissolves and the mixture is smooth.
Meanwhile, in a medium saucepan, combine the sugar, corn syrup, honey and 1/3 cup plus 2 tablespoons of water and bring to a boil, stirring to dissolve the sugar.
Cook the syrup over moderately high heat until it registers 250 on a candy thermometer.
Immediately pour the hot syrup into the bowl of a stand mixer fitted with the whisk.
Scrape in the gelatin mixture and beat at high speed until a smooth white foam forms, about 4 minutes.
Spread the marshmallow in the prepared pan and smooth the surface.
Press a lightly greased sheet of parchment paper on the surface and let stand until set, 3 hours.
Run a sharp knife around the marshmallow.
Very lightly dust a work surface with cornstarch and invert the cake pan onto it, tapping to release the marshmallow.
Using a lightly greased sharp knife, cut the marshmallow into 1 1/2-inch pieces.