Bath Bomb Cupcakes

Cool Science


bath bombs are *always* in style for a scented, spa-time treat. and this presentation, in the silicone cupcake molds, is such a perfect way to package them for gift-giving. super cute and stays in shape!

45 minutes

maker checklist

  • 1/2 cup corn starch
  • 1/2 cup epsom salt
  • 1 cup baking soda
  • 1/2 cup citric acid
  • 1 tsp. olive oil
  • 1 tsp. water 
  • 1 tsp. essential oil
  • food or soap coloring
  • pipette
  • mixing bowl + spoon
  • silicone cupcake molds
  • half-sphere mold (optional)



combine the dry ingredients in a large bowl, and mix them well.


combine the olive oil, essential oil and water in a small bowl; stir gently.


dribble the wet ingredients into the dry ingredients using a pipette or a very steady, slow pour.

important! add the wet ingredients to the dry ingredients drop by drop, stirring continuously as you do, so the mixture doesn’t fizz and bubble up.


mix! ultimately, it should feel like fluffy, damp sand that stays together when you squeeze it in your hand.

tip! if it’s too dry, add a drop of water or oil, but be careful not to get it too wet!


color your mixtures by separating the white mixture into small bowls and adding food coloring or soap colorant to each.

tip! mix a few colors, but reserve a bowl of plain white for layering and contrast!


layer the colors into a cupcake mold until you’ve created a small mound on top, packed tightly.


pack a bit more of the mixture into a small bowl that is about the same size as your cupcake mold.



invert the domed top onto the cupcake; pressing firmly so the layers adhere. lift the dome and voila!


give the dome a tap to loosen the mix before lifting the cap.