Prepare a baking sheet or other surface by lightly spraying with baking spray or covering with parchment paper or non-stick aluminum foil.
Measure out the corn flakes and set aside.
Combine the corn syrup and the granulated sugar in a small saucepan and heat over medium-low heat until the sugar has melted.
Add the peanut butter and vanilla if using and stir until the peanut butter has melted.
Turn off the heat, but leave the pot on the burner and add the cornflakes.
Quickly stir to combine before the mixture cools off.
Lightly coat 2 spoons or a cookie scoop with baking spray and drop onto prepared baking sheet.
Allow to cool completely before storing in an air-tight container.
Notes
Measure out ingredients first and preparing a flat surface before starting to cook.
For easier clean-up spray the corn syrup and peanut butter measuring utensils with baking spray before filling.
If you keep the finished mixture over a very low heat or sitting on a cooling burner, it will give you a few extra minutes for forming before it sets.
The easiest way to clean the pan is to scrap out all of the cooled mixture you can and then soak the pan in hot water for 1- to 15 minutes, then clean as usual.
If adding sprinkles or jimmies use them immediately after dropping each piece so that they stick.
Store between sheets of plastic wrap, wax paper, or parchment paper in an airtight container.