In a large bowl or stand mixer fitted with a paddle attachment, cream together the butter and sugars until light and fluffy.
Add the eggs, additional egg yolk, and vanilla and beat just until combined.
In a separate large bowl, whisk together the flour, oats, salt, cinnamon, baking powder, baking soda, and cornstarch.
Add to the mixing bowl and mix lightly, do not fully incorporate yet.
Add the coconut, cornflakes, and pecans and mix just until combined.
Fold in the caramel bits and chocolate chips with a rubber spatula.
Measure the dough out into 1/4 cup sized portions and roll the dough into tall balls and place on a cookie sheet or in a container and chill for at least 1 hour and up to 48 hours.7
Preheat oven to 350°F and line a large baking sheet with parchment paper or a silicone baking mat. Make sure there are at least 4 inches between each ball of dough and the edges of the pan, these cookies are big and will spread. Bake for 11 to 14 minutes until the edges are golden brown and the center is still puffy.8
Remove from the oven and allow to cool on the baking sheet for a few minutes before transferring to a wire rack to cool completely.