Allow the milk mixture to boil for 2 minutes. Remove from the heat and slowly whisk in the cornstarch slurry. Return to heat until slightly thickened, about 30 seconds, stirring constantly.
Once thickened, remove from heat and stir in vanilla extract and Fruity Pebbles. Place the lid on to steep, and let cool to room temperature.
2 teaspoons vanilla extract, 2 ½ cups Fruity Pebbles cereal
Strain into an airtight container, squeezing out all extra liquid from the cereal. Chill for at least 8 hours.
Once chilled, freeze in the ice cream maker according to the manufacturer's instructions. Mine takes about 25 minutes.
Enjoy right away or place in an airtight container and freeze for 4-6 hours.