This recipe is not for the faint of heart. It is decadent and rich! I got this from a baking recipe book and it has become a staple. We love it and I usually have all the ingredients in my pantry. Once, I decided to make them at the last minute, so they were still warm when I served. Everyone loved them warm. Now, sometimes I will warm for a few seconds in the microwave before eating. Best with a large glass of milk.
Preheat oven to 350 degrees. Generously spray a 13x9 inch pan with nonstick cooking spray.
In a mixer, blend butter and both sugars. Add eggs, vanilla, and oats and blend well. Fold in flour, baking powder, baking soda, and salt. then fold in chocolate chips.
Spread batter in prepared pan. Top with dollops of dulce de leche and then swirl or smear the dulce de leche into batter.
Bake for 38 minutes or until batter is set (not wobbly and jiggly). If they seem browned around the edges but jiggle in the center, reduce oven temperature to 325 degrees and continue baking 10-15 minutes longer or until set.
Refrigerate or freeze 1 hour. Cut into large hunks or blocks.
NOTE: This makes a thick hunk of dessert. I usually want to stretch it out and I use a 14x11 inch pan. It it still thick, but I can serve more. I usually don't put in the refrigerator or freezer. I let them cool on my counter. ^(,^