Making Ghostly Ganache Brownies can be straightforward when you follow these steps:

1. Preheat the Oven: Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking dish or line it with parchment paper for easy removal.
2. Melt Butter: In a medium saucepan, melt the unsalted butter over low heat. Remove from heat and stir in granulated sugar until well combined.
3. Add Eggs and Vanilla: Beat in the eggs, one at a time, followed by the vanilla extract, until the mixture is creamy and smooth.
4. Mix Dry Ingredients: In a separate bowl, sift together the flour, cocoa powder, salt, and baking powder.
5. Combine Mixtures: Gradually fold the dry ingredients into the wet mixture, stirring until just combined. Be careful not to overmix.
6. Pour Batter: Pour the brownie batter into the prepared baking dish, spreading it evenly.
7. Bake: Place in the preheated oven and bake for 30-35 minutes, or until a toothpick inserted in the center comes out clean.
8. Cool: Allow the brownies to cool in the dish for about 20 minutes, then transfer to a wire rack to cool completely.
9. Prepare Ganache: While the brownies are cooling, heat the heavy cream in a saucepan over medium heat until just simmering. Remove from heat and pour over the chopped semisweet chocolate. Allow it to sit for a few minutes.
10. Stir Ganache: After a few minutes, stir the mixture until it’s smooth and well combined. Let the ganache cool slightly.
11. Top Brownies: Once the brownies are completely cool, pour the ganache over the top, spreading it evenly.
12. Decorate: If desired, place ghost-shaped chocolate decorations on top of the ganache for a spooky touch.
13. Slice and Serve: Once set, slice the brownies into squares and serve.

With these clear steps, you’ll be able to craft your own Ghostly Ganache Brownies with ease!