Line an 8×8-inch square tin with parchment paper in a crisscross pattern, ensuring a 1-inch overhang on all sides. Generously grease with nonstick spray and set aside.

In a large stock pot, pour in the cold cranberry juice and sprinkle the powdered gelatin evenly over it, whisking gently to combine.

Add the boiling cranberry juice and granulated sugar to the mixture, whisking thoroughly until smooth.

Place the pot over high heat and bring the mixture to a boil (about 5 minutes). Once boiling, reduce heat to medium and continue to simmer, stirring occasionally, until the temperature reaches 107°C / 225°F (about 20-25 minutes).

Remove from heat and gently remove large bubbles using a skimmer or fine mesh strainer.

Carefully pour the mixture into the prepared pan. Refrigerate until firm, at least 4 hours or overnight for best results.

Once firm, coat a large chopping board with granulated sugar and flip the cranberry slab onto the sugared board, peeling away the parchment.

Spread more sugar over the slab until fully covered on both sides.

Using the back of a knife, lightly score the surface into squares (49 for 7x7 rows or 64 for 8x8).

Using a sharp, well-oiled knife, cut the slab along the scored lines, then roll each square in sugar to coat all sticky sides.

Arrange coated candies on a tray, ensuring they don’t touch each other. Allow to dry at room temperature for 1-2 days, or until the sugar crystallizes.

Layer candies between sheets of parchment in an airtight container. They can be stored at room temperature for up to a month.