Preheat oven to 350°.
Grease a 9x9 pan.
Beat together butter, sugar, peppermint extract and vanilla extract.
Add eggs one at a time, beating well between each addition.
Stir together flour, cocoa powder and salt.
Gradually add to butter mixture.
Mix in baking soda.
Fold in chocolate chips.
Scrape batter into prepared pan, spreading evenly.
Scatter crushed peppermint candy over the top.
Bake for 25 minutes, until brownies begin to pull away from the edges of the pan.