1/2 cup salted butter
1/2 cup shortening
1 cup brown sugar
1/2 cup white sugar
2 tsp. vanilla extract
3/4 tsp salt
1 tbsp. white vinegar
2 large eggs
1 tsp. baking soda
2 cups unbleached all-purpose flour
1 - 1/4 cup brownie mix, dry (straight from the box)
2 cups semisweet chocolate chips
Preheat oven to 350 degrees F. In a large mixing bowl, cream together the butter, shortening, sugars, vanilla, salt, and vinegar. Beat in the eggs, then the baking soda and flour. Stir in the brownie mix and chips. Drop the dough by a small tablespoonful onto baking sheets. Bake for 10-12 minutes. Remove from the oven and transfer to a rack to cool.
Tips: The dough will be a little dry and stiff, but not crumbly! add a little milk if needed!