Creating these Marshmallow Ghost Brownies is fun and easy. Follow these simple steps:

1. Preheat your oven: Set your oven to 350°F (175°C) and grease a 9×13-inch baking pan.
2. Melt Butter: In a medium saucepan over low heat, melt the butter completely. Remove from heat.
3. Combine Sugar and Eggs: Stir the granulated sugar into the melted butter until smooth. Then, add the eggs one at a time, mixing well after each addition, followed by the vanilla extract.
4. Sift Dry Ingredients: In a separate bowl, sift together the flour, cocoa powder, baking powder, and salt.
5. Combine Mixtures: Gradually add the dry ingredients to the butter mixture, stirring until just combined.
6. Bake the Brownies: Pour the brownie batter into the prepared baking pan, spreading it evenly. Bake in the preheated oven for about 25-30 minutes, or until a toothpick comes out with a few moist crumbs.
7. Add Marshmallows: Once baked, remove the brownies from the oven and immediately sprinkle the mini marshmallows evenly on top. Return to the oven for about 3-5 minutes until the marshmallows start to puff up.
8. Cool the Brownies: Let the brownies cool in the pan for about 15 minutes before transferring them to a wire rack.
9. Decorate: Once cooled, use chocolate chips to create ghost faces, adding edible eyes if desired.
10. Slice and Serve: Cut the brownies into squares, arranging them on a platter for serving.

By following these easy steps, you will create a decadent treat that embodies the spirit of Halloween!