Preheat oven to 350 degrees f.  Line an 8X8 baking pan with parchment paper or use cooking spray to grease the pan.

Combine the melted butter, Swiss Miss mix, eggs, and vanilla extract in a large bowl. Beat until smooth.

Stir in the flour, baking powder, and salt together in a separate bowl. Fold the dry ingredients into the chocolate mixture and mix until combined. Add sour cream and mix well. Add chocolate chips or other " add-ins". combine.

Pour the brownie batter into the prepared baking pan and bake for 20 minutes, or until a toothpick inserted into the center comes clean.

Let the brownies cool completely before cutting and serving.