In a large bowl, combine baking soda, citric acid, cornstarch and Epsom salt.
Use a separate cup or small bowl to combine almond oil, water and essential oil.
Pour wet mixture into dry mixture; whisk together until fully combined.
Lightly spray witch hazel a couple times until mixture is wet enough to hold its shape (see video above).
Place a Mickey candy decoration in the center. Firmly press bath bomb mixture into the mold, only filling it up halfway.
Let bath bombs dry overnight before carefully removing from mold.