Preheat the oven to 350 degrees F (175 degrees C).
Whisk applesauce, brown sugar, white sugar, egg white, oil, milk, and vanilla extract together.
Stir flour, baking soda, cinnamon, and salt together in a separate bowl; add to the applesauce mixture. Stir in oats and chocolate chips. Spread dough evenly into an ungreased 9x13-inch baking pan.
Bake in the preheated oven until golden brown, 20 to 25 minutes. Cool completely before cutting into 16 bars.