Christmas Tree Brownies

Name: Christmas Tree Brownies
Prep time: 10 min
Total time: 10 min
Cuisine: American
Ingredients: Cooking spray; 1 box brownie mix, plus ingredients called for on box; 3/4 c. (1 1/2 sticks) butter, softened; 4 c. powdered sugar; 1 tsp. pure vanilla extract; 2 tbsp. heavy cream; Pinch kosher salt; Green food coloring; 6 candy canes; Sprinkles, for decorating