Preheat oven to 350 degrees F. Line a baking sheet with parchment paper.
In a large bowl cream the butter and sugars together. Add eggs and vanilla and mix until incorporated.
Add flour, baking powder, baking soda, salt, and oats and stir well to combine. Stir in corn flakes and chocolate chips.
Spoon large tablespoons of the dough onto prepared cookie sheet.
Bake at 350 degrees F for 10-12 minutes or until set on the top.
Cereal: if you don't have corn flakes, feel free to use rice krispies, lightly crushed Chex, or frosted flakes cereal.
Coconut: add 3/4 cup sweetened shredded coconut.
Nuts: add 1/2 cup chopped pecans or walnuts.
Make Ahead Instructions: Make the dough up to 1 day in advance and store in the fridge. Or make the cookies 1-2 days ahead of time.Freezing Instructions:Freeze the dough or cookies (cooled completely) in a freeze safe container for up to 3 months. Allow a few extra minutes bake time if baking dough from frozen.