1. Preheat oven to 350°F (175°C). Line a 9×13 inch baking pan with parchment paper.

2. In a large bowl, whisk together melted butter and granulated sugar until combined.

3. Beat in eggs one at a time, then stir in vanilla extract.

4. In a separate bowl, combine flour, cocoa powder, baking powder, and salt. Gradually add dry ingredients to wet ingredients, mixing until just combined.

5. Divide the batter into two bowls. Tint one bowl with orange food coloring and the other with black food coloring.

6. Drop alternating spoonfuls of orange and black batter into the prepared pan. Swirl gently with a knife for a marbled effect. Sprinkle with chocolate chips and Halloween sprinkles.

7. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out with moist crumbs.

8. Let cool completely before cutting into squares. Enjoy your Classic Halloween Brookies!