
Much like making any dark-hue buttercream, whipping up black buttercream can be a frustrating task for many a cake decorator. Use the recipe below to make buttercream fit for any Halloween cake.
Black Buttercream
Level: Easy
What You Need
Pro Tip: Gel paste food color won’t hinder or weaken the texture and stability of your buttercream. If you use liquid food coloring, you’ll find that your lovely homemade frosting will look more like unattractive soup than anything you’d love to smother a cake with.
Instructions
1. Make Chocolate Buttercream

Step one in making black buttercream is to … make chocolate buttercream! The dark color makes it easier to blacken the buttercream without any bitter or weird tastes that over-using food coloring can cause.
Make sure that your buttercream is free of any lumps and clumps. We’d recommend using couverture dark chocolate melted in a bain marie and then poured into the buttercream before lightly whipping the mixture together. To darken the chocolate a little more, add in around 1 tablespoon of sifted cocoa powder.
2. Add Color

Good to Know: A lot of food colors deepen over a short space of time, so try letting your buttercream sit for about 30 minutes before checking it. We always find this typically happens with blacks, reds, purples and blue shades.
A lot of food colors deepen over a short space of time, so try letting your buttercream sit for about 30 minutes before checking it. We always find that this happens with blacks, reds, purples and blue shades.
3. Mix

Use a spatula to slowly mix the buttercream by hand. Make sure to scrape the bowl’s sides and incorporate the chocolate buttercream and black food color together. It’s important to mix slowly, it’ll help avoid your buttercream from having the not-so-nice surprise of streaky unmixed colors.
Now your buttercream’s ready for piping!
I've done this a lot and it works. Give it a try.