In a small heat-safe container, add 6 ounces of shea butter and 4.5 ounces of cocoa butter. Place the container in the microwave and melt the butters using 30-60 bursts. The cocoa butter takes a little while to melt. Be careful when removing it from the microwave, as it may be very hot.

Add 0.5 ounces of Warm Vanilla Sugar Fragrance Oil, 0.5 ounces of polysorbate 80, and 1.5 ounces of glycerin to the melted butters. Use a spoon to thoroughly incorporate. Set aside.

Place a fine mesh sifter over a large container. Add 25 ounces of baking soda, 7 ounces of citric acid, and 2.5 ounces of cream of tartar. Pour the ingredients through the sifter to get rid of chunks and use a whisk to mix. Very carefully, add 13 ounces of SLSA to the large container (do not put it through the sifter). We recommend adding the SLSA last because it’s extremely fine and powdery and can become airborne very easily. You may want to wear a mask during this step to avoid breathing in any SLSA - it can be irritating. Once everything’s added, slowly mix together the dry ingredients.

When the liquid ingredients are about 180° F, add 1/3 to the dry ingredients. This is quite hot, so gloves are recommended. The hotter the liquid ingredients are when added, the softer the final “dough” will be. Adding the liquid when it’s hot reduces the need to microwave it later. Use your hands to incorporate the liquid and powder ingredients together. If you prefer, you could also use a stand or hand mixer for this step, but we prefer using our hands.

Continue adding the liquid ingredients in 1/3 increments to the dry and mix together until fully incorporated. The final texture will be very similar to bread dough – soft, workable, and slightly sticky. The texture of the mixture depends on the temperature of the butters. The warmer the dough, the softer it will be. We found a dough temperature of about 85-100° F is a great moldable texture. If your dough is cooler than that, place the entire mixture into the microwave for 10-20 seconds to warm it.

You will have about 60 ounces of mixture. Split the batch into 2 equal containers. You can eyeball it or weigh it, depending on your preference.

To one container, add 3/4 teaspoon of Copper Sparkle Mica and use your hands to thoroughly mix. If you’d like a darker color you can add more mica, just keep in mind this may leave behind more color in the bathtub.

Once the mica is thoroughly mixed and there are no streaks of color, lay down a sheet of wax paper on the counter and sprinkle on a thin layer of baking soda. This prevents the bath truffles from sticking to the counter, and it's used to roll up the batch.

Lay the brown mixture on the wax paper and begin forming it into a rectangle shape. Place the white mixture on top and use your hands to spread it evenly onto the brown. Create a flat rectangle shape – about 14 inches long by about 7-8 inches tall.

Use the wax paper to roll the bath truffles. The bars may stick to the paper slightly, but that’s okay. You can use your hands to smooth out the roll if necessary.

Continue rolling and use your hands to help create a smooth, even log.

Once you’re happy with the shape, sprinkle the top with Epsom salt and press it gently into the log to help it stick.

Use a sharp non-serrated knife to cut the log into bars. If it's too soft, it can be a little sticky and needs to be handled very carefully. You can wait for about 30 minutes for it to harden slightly, or cut the bars very gently. How soft the log is will depend on how hot the butters were and if you placed the mixture in the microwave.

Once the bars are cut, place them gently on a piece of parchment paper or wax paper. Use your hands to give them a more uniform shape, smooth the edges, or fix any chunks that may have fallen off while cutting. Sprinkle more salt on top if you’d like. As the butters in the bath truffles cool, they become hard. It takes about 3-4 hours for the bars to become firm depending on your room temperature. It can be hard to wait, but be patient!

Once you’re ready to use the bath truffles, place them in the tub for a slow fizzing reaction with a small amount of foamy bubbles. If you want to activate more bubbles, hold the bar directly under the running bath faucet while breaking off small amounts of the bar.