Preheat the oven to 350 degrees Fahrenheit. Spray a mini muffin tin (usually 24 cavity) with oil and set aside. Add the 1 cup of chocolate chips and butter or oil to a bowl. Melt in the microwave using 30 second increments, stirring between each until fully melted.
Meanwhile, beat together the eggs and sugar for 1 minute. Beat in the vanilla.
Beat in the melted chocolate.
Fold in all dry ingredients, then the final 1/2 cup of chocolate chips.
Use a greased spoon or small greased cookie scoop to scoop the batter into the tin.
Bake for 14-20 minutes or until a toothpick comes out clean.
Let cool completely, then use a knife to carefully lift each brownie out of the tray. Enjoy!