Make the Potion Bottles:

1. Melt your candy melts (or white melts + candy color) according to package directions.
2. Pour into the mold cavities—green in one set, purple in another.
3. Chill in the fridge for at least 30 minutes, or until fully set. Carefully de-mold and set aside.

Bake the Cake:

1. Preheat the oven to 350°F and grease a 13×9 baking pan (or use a disposable pan for easy transport).
2. In a large mixing bowl, combine the cake mix, dry pudding mix, water, oil, and eggs. Mix until well blended and pour into the prepared pan.
3. Bake according to the cake mix instructions and let the cake cool completely.

Make the Frosting:

1. Beat the butter until smooth and creamy.
2. Add half the powdered sugar and mix to combine.
3. Add the remaining sugar, heavy cream, and vanilla. Beat until fluffy.
4. Add a few drops of orange gel food coloring to create a light orange hue.
5. Scoop out about 1/3 of the frosting and tint it a deeper shade of orange for piping.

Decorate:

1. Frost the cooled cake with the light orange buttercream.
2. Press the potion bottle candies gently into the frosting, spacing them out across the surface.
3. Transfer the deeper orange frosting into a piping bag fitted with a large star tip and pipe a decorative border around the cake.

Serve:

1. Slice, serve, and cast a sweet spell over your Halloween crowd.