Line an 8x8-inch baking pan with parchment paper, letting edges hang over for easy lifting. Lightly grease the parchment paper.

In a medium saucepan over low heat, combine white chocolate chips and sweetened condensed milk. Stir constantly until mixture is silky smooth and fully melted with no streaks or lumps, about 3-5 minutes.

Remove saucepan from heat and stir in cotton candy extract, mixing thoroughly to infuse the base completely.

Evenly divide the warm fudge mixture into three bowls. Add a drop or two of purple, blue, and pink gel food coloring to each bowl and mix until you have three vivid pastel shades.

Drop spoonfuls of each colored mixture into the prepared pan, alternating colors to scatter them around (about 6-8 spoonfuls of each color).

Use a clean knife or skewer to gently swirl the colors together with 5-6 figure-eight motions, creating a galaxy effect. Stop once you see a clear cosmic pattern to avoid muddy colors.

Sprinkle the top with edible glitter or star sprinkles while surface is still soft.

Refrigerate for at least 2 hours until perfectly set (overnight is even better).

Let sit at room temperature for 5 minutes, then lift from pan using parchment paper and cut into 16 squares with a sharp knife, wiping blade between cuts.