In a large bowl, cream  the brown sugar, sugar, vanilla, oil, and eggs.

In a separate bowl, whisk the flour, baking soda, and salt together. Add to the creamed mixture and mix until combined. Mix in the oats and cornflakes until evenly distributed.

Using a large cookie scoop, scoop the dough onto an ungreased cookie sheet. This batter might be a little dry. You may have to squish it together with your hands to get it into a ball when you put it onto the pan.

Bake for 8 to 10 minutes at 375 degrees just until edges are lightly browned. If you cook these too long you will end up with a crunchy cookie. Allow to cool on the cookie sheet for a minute and then remove to a cooling rack. Allow cookies to cool completely. Makes 2 dozen large cookies.