Preheat the oven to 350°F. Line a 9 x 9-inch non-stick baking pan with parchment paper.
In a large mixing bowl, combine brownie mix, eggs, vegetable oil, Dr Pepper, semi-sweet chocolate chips, and vanilla extract. Mix together well.
Pour into the prepared baking pan.
Bake for 32 minutes or until a toothpick comes out almost clean.
Let brownies cool.
Remove from the pan using the parchment paper and slice before serving.
