1. Cream butter and sugar until fluffy. Add orange zest and essence, then eggs one by one. Fold in dry ingredients and bake three 6-inch layers at 180°C for 25–30 minutes.

2. Cool layers completely. Wrap and freeze if making ahead.

3. Heat sugar and egg whites over simmering water until dissolved. Whip until glossy, then add butter gradually. Mix in orange extract. Divide: color 1/3 orange, add melted chocolate and black coloring to rest.

4. Microwave chocolate and cream in 30-second intervals until smooth. Cool slightly before dripping.

5. Whip egg whites to stiff peaks. Add sugar gradually, then vanilla and salt. Pipe ghost shapes and bake at 100°C for 30 minutes. Draw faces once cooled.

6. Layer cakes with frosting between each. Crumb coat, chill, and cover with chocolate buttercream. Add orange stripes, chocolate drip, and finish with meringue ghosts.