Preheat oven to 350 degrees F. Combine brown sugar, oil, butter, vanilla, salt, baking soda and egg in a large mixing bowl. Stir until well combined.
Weigh or lightly spoon flour into measuring cup; level with a knife. Add flour, oats, nuts and chocolate chips to sugar mixture. Stir until just combined.
Scrape the dough into a 9-inch glass pie plate coated with cooking spray and spread to the edges with a spatula. Bake at 350 degrees for 13 minutes or until set.
Cool slightly on a wire rack. Cut into 8 wedges and ENJOY!!