Preheat oven to 350 degrees. Grease an 8x8 square baking pan, or line it with parchment paper, spray with non-stick cooking spray.
In a medium bowl, combine flour, cocoa and salt and mix together with a whisk, set aside.
Melt butter in microwave until melted in a large microwavable bowl or after melted, transfer to a large bowl.
While the butter is still hot, mix in the oil and sugar and and whisk together until mixed well.
Add applesauce and vanilla and again mix until well combined.
Next, add the flour to wet ingredients mixture and whisk together until well combined.
Pour the brownie batter into the prepared pan and spread evenly.
Bake for 28-30 minutes, or until a toothpick comes out with a few moist crumbs.