Preheat oven to 350-degrees.
In a medium-sized microwave-safe bowl, combine butter and shortening.
Microwave for 15 seconds at a time until just melted together. Stir and set aside to cool.
When butter mixture has cooled, add baking cocoa, sugar, vanilla, and eggs. Mix well.
In a separate bowl, combine flour, baking powder, salt, and chocolate chips.
Stir dry mixture into chocolate mixture until combined (it will be fairly thick).
Pour mixture into a greased 9x13 baking dish (or 9x9 if you want them to be thicker).
Bake for 30 minutes or until brownies just start to pull away from the sides of the pan (if you are using a 9x9 dish you may need to add a few minutes). Do not over bake.
Cool at least 20 minutes before cutting. Enjoy!