Preheat the oven to 325 degrees F. Line a large rimmed sheet pan with parchment paper and set aside. Mix the first seven dry ingredient in a medium mixing bowl.
Place the egg whites in a small bowl and beat with a whisk (or egg beater) until ultra frothy. Then stir the melted butter and vanilla extract into the flour mixture, and fold in the frothy eggs whites.
Mix half the mini chocolate chips into the batter. Then spread the brownie bark batter evenly over the entire surface of the prepared sheet pan. Sprinkle the remaining chocolate chips over the top.
Bake for 20-25 minutes...25 for extra crispy brownie bark. A little less if you want it to have a chewy note. Slide the parchment off the baking sheet while the brownie bark recipe is still hot. Cut immediately into pieces, before it has time to cool, then cool completely before serving or storing.