1. Preheat oven to 350°F (176°C). Line a 9-inch square cake pan with aluminum foil.
2. Whisk together the melted butter, sugar and vanilla extract in a large bowl.
3. Add eggs and whisk until well combined.
4. In a separate medium sized bowl whisk together flour, cocoa, baking powder and salt. Slowly add dry ingredients to the egg mixture and whisk until well combined.
5. Stir in the muddy buddies.
6. Pour the batter into the prepared pan and spread evenly. Sprinkle a few more crushed muddy buddies over the top.
7. Bake for 18-21 minutes, or until a toothpick comes out with a few moist crumbs.
8. Remove brownie from oven and allow to cool for 3-4 minutes, then remove from pan to a cooling rack to finish cooling.
9. Once cool, use the aluminum foil to lift the brownies out of the pan, then cut into bars.