Preheat oven to 350 degrees. Prepare a baking sheet by lining it with parchment paper or use a baking stone.
In a medium bowl, beat together the palm oil and sugar with a hand blender.
Add the rice milk, cocoa powder, salt, vanilla, and peppermint oil, and beat again until incorporated.
Add the gluten free flour and baking powder to the palm oil mixture and beat until a dough forms.
Cover the dough with plastic wrap or cover the bowl with a lid and let rest for 5 minutes. This allows the thickeners in the flour to firm up the dough a bit.
After the dough has firmed up a bit, pinch off about 1 Tablespoon of dough and roll into a ball. Set onto your prepared baking pan and press to flatten slightly.
Bake for 11 to 12 minutes in the oven. Allow the cookies to cool for 5 minutes on the baking sheet before removing to a cooling rack to cool completely.
Once the cookies are completely cooled, whisk together the powdered sugar, rice milk, and the natural green food color to make the green icing.
Drizzle the icing on the completely cooled cookies and ENJOY!