Preheat oven to 350 degrees. Spray a glass 9x13 pan with cooking spray and set aside.
In a medium-sized bowl or in a stand mixer, combine softened butter, light brown sugar, granulated sugar, egg, and vanilla. Beat on medium speed for 2-3 minutes or until creamed.
Add flour, oats, baking powder, and sea salt. Mix for another minute or two until well combined. Scrape sides down halfway thru mixing.
Next, add chocolate chips, shredded coconut, crushed cereal, and chopped nuts. Mix until just blended.
Scoop cookie mixture out into prepared 9x13 pan and evenly spread over the pan. (I use a plastic baggie over my hand and push it down evenly because the dough is thick and can be hard to spread with a spoon.)
Once the dough is evenly spread into the pan, bake it at 350 degrees for 12-16 minutes or until edges are beginning to brown and a toothpick inserted in the center comes out clean.
Let cool and cut into squares.
Enjoy!
Recipe by Real Life Dinner at https://reallifedinner.com/cowboy-cookie-bars/