Add 1 cup of cold water to a small saucepan. Then add the agar agar powder and sugar and mix until both are incorporated.
Turn the heat to high and bring the mixture to a boil, stirring constantly. Once the mixture has come to a rolling boil, turn the heat down to medium-low and allow the mixture to simmer for 5-10 minutes until the liquid is completely clear.
Add the coconut milk and mix until incorporated. Then pour into ghost molds and allow to solidify at room temperature. Once they are firm, slide out of the molds. Use food coloring gel to paint on spooky faces right before serving.
Notes
This recipe will make enough coconut agar to fill approximately 24 small ghost molds, or one 9" x 13" baking dish, if you opt to use cookie cutters.
The food coloring gel will start to bleed after about 1 hour, so be sure to paint it on right before serving.