With a hand mixer or stand mixer, beat the palm oil until softened.
Add in slowly the powdered sugar, rice milk, and vanilla. Beat until mixed thoroughly and smooth.
If you need, you can adjust the thickness to your liking by adding a little bit of rice milk (1 teaspoon at a time) to make it less thick, or powdered sugar (1 Tablespoon at a time) to make it more thick.
Optional: add some natural food color powder to add color. I use McCormick natural food color powders, start out with a small amount and add more until you reach the color you like.
*If you don't want to use palm oil, you can use completely softened dairy free butter and omit imitation butter flavor. You may need to add a bit more powdered sugar to get the stiffness/structure in the frosting that you prefer.