Butter a straight-sided 8-inch square cake pan and set aside. Line with a single sheet of waxed paper.

Attach a candy thermometer to the side of a saucepan. Add the sugar, corn syrup, and 1/4 cup water to the pan and bring to a boil, stirring until the sugar has just dissolved.

Continue to cook until the syrup reaches 255 to 260°F on the candy thermometer, about 12 minutes.

Meanwhile, in the bowl of a stand mixer fitted with the whisk attachment, beat the egg whites until stiff peaks form, about 2 minutes.

When the syrup reaches temperature, slowly (and carefully) drizzle it into the egg whites with the mixer on medium-low speed.

Once the syrup is fully combined, add the vanilla, increase the speed to high, and continue to beat until the mixture is no longer glossy and holds its shape, 7 to 8 minutes.

Remove the bowl from the stand mixer and, moving quickly, fold in 1 cup of the gummy candies using a wooden spoon.

Transfer the mixture to the prepared pan and do your best to spread into an even layer—it will be very sticky.

Arrange the candies evenly in five rows of five, lightly pressing them to ensure they stick.

Allow the divinity to cool completely, about 1 hour.

Cut into 1 1/2-inch squares with a knife lightly sprayed with nonstick cooking spray, slicing between the candies on top.