How to make cupcake bath bombs
Cupcake bath bombs are always one of the most popular kinds. They look so delicious!
The usual recipe uses an egg and sugar meringue-type mix for the topping, in order to get a consistency that can be piped into pretty shapes. Personally, I don't like putting sugar in my tub, so I'm also going to give my own sugar-free recipe.
These are basic proportions, so if you want to make larger batches, just multiply the quantities.
Cupcake bath bomb recipe with piped topping – uses sugar
For the base, you need:
- 2 cups of baking soda
- 1 cup of citric acid
- Fragrance oil – about a tsp, but you can use less or more according to how strong you like the smell. Normally I recommend essential oils for making spa products, but with cupcake bath bombs you really want something yummy-smelling, and the best options for that are purpose-made fragrance oils. Brambleberry has some really great ones – I like their Butter Cream and Snickerdoodle fragrance, but there are tons to choose from.
- A few drops of color to produce a nice rich cake effect – again, Brambleberry has some great choices for cupcake bath bombs.
- Witch hazel or water in a spritz bottle
- Cupcake liners, and a muffin tray to put them in
And here are some optional extras you can add if you want:
- 1 tbsp of a nice nourishing nut or seed oil (eg almond oil), for silky-smooth skin
- 1 tsp Bentonite clay – this produces a harder bath bomb
- Up to 1 tbsp sodium lauryl sulfate – this produces bubbles in the bath
Mix up the dry ingredients in a large bowl. You can use a whisk (but be careful not to breathe in the powders), or rub then together with your hands – make sure they're really well mixed, so the base is nice and smooth. If you're using sodium laurel sulfate, then be especially careful not to breath it in, as it's really irritating – you may want to wear a mask.
Now add the color, fragrance, and oil if you're using it, and rub it in really well with your hands. It'll probably take about five minutes of rubbing in to get the color and fragrance evenly mixed in.
Now, take your little bottle of witch hazel or water, and spritz a little into the mix. Mix it in immediately. Keep spritzing and mixing until the mixture has the right texture. How do you know? Well, take a handful of mixture and squeeze. If it stays in a nice clump, it's about right. If it falls apart into little clumps, it needs more moisture. (If you add too much moisture it'll start fizzing.) As a clue, when it's about right it will feel like damp sand.
Now put the mixture into your paper cupcake liners, inside the muffin tray (if you're going to be doing this a lot, you might want to invest in cupcake molds). Pack it down well – the better packed it is, the less chance the bath bombs will crumble before they get to the bath.
Put to one side, and start on your topping mix.
For the topping, you need:
- 3 tbsp of meringue powder or powdered egg whites
- 1 lb powdered sugar
- 1/4 tsp of cream of tartar
- 5-6 tbsp warm water
- 1tsp fragrance oil – Brambleberry have a nice Cream Cheese Frosting fragrance, but of course you can go for any flavor you might naturally find on a cupcake. Island Coconut is a nice one. Any vanilla will work well, but if you use a fragrance that includes vanilla, remember to add an equal amount of vanilla stabilizer, to stop discoloration.
- A few drops of color, to suit the fragrance.
(Credit for this topping goes to Anne Marie of Brambleberry, as I never use this recipe! I use the sugar-free version I give below.)
You probably want an electric whisk for this, as it's hard work by hand, but you may need to fold things loosely together before you turn on the mixer, or you'll have powder everywhere!
Mix together the meringue powder with the warm water. Now add the powdered sugar, the cream of tartar, and the fragrance and color. Mix till it forms stiff peaks.
Spoon the mix into a piping bag – or if you don't have one, cut the corner off a regular freezer bag. Pipe the topping onto the cupcake bases, in a pretty spiral. Sprinkle on some decorations if you like. Leave overnight to dry.
Cupcake bath bomb recipe with spread top – no sugar
As I was saying, I'm not a fan of sugar in my bath tub! So I make my cupcake bath bombs with an ordinary bath bomb mix.
Make the base the way that I described above, but when you pack in into the molds, instead of making the top flat, put some more mix in and make it rounded. You want it curving right out of the paper liner, as it if had risen in the oven.
Now make a second batch of mix with the same formula, but a different color and flavor. I like a chocolate topping, so I might use this recipe:
- 2 cups of baking soda
- 1 cup of citric acid
- 1 tsp Brambleberry's Dark Rich Chocolate fragrance oil
- A few drops of color to produce a nice rich chocolate color
- Witch hazel or water
So I mix this second batch in exactly the same way as I made the base. Then I take a spatula and smear a good layer of the 'chocolate frosting' onto the rounded top of my cupcake. I like to leave in the spatula marks – it looks more authentic!
Then I just decorate the 'frosting' with a few sprinkles, or perhaps by sprinkling a little epsom salt on top to look like a sugar topping. Leave overnight to dry, and you're done!