Heat oven to 350. Spray an 8" x 8" baking pan w/ cooking spray. In small bowl, whisk together flour, cocoa and baking powder. Melt 1/2 cup butter in bowl in microwave.
Pour butter into lg bowl, whisk in chocolate chips. Whisk in sugar and eggs. Whisk in dry ingredients. Pour mix into pan and bake 20-25 mins, or until a toothpick inserted in center comes out clean.
In another bowl, beat 1/4 cup butter, powdered sugar and peppermint extract until smooth. Add milk. Stir in crushed candy canes. Frost cooled brownies. Melt chocolate chips in microwave, in a bowl. Stir in oil. Drizzle over brownies.