Preheat oven to 350 degrees F. Spray a 9″ x 13″ baking pan thoroughly with non-stick spray. Set aside.

In a medium bowl, sift the dry ingredients together. Set aside.

In a large mixing bowl, combine the water, coconut milk, and vanilla extract. Add the dry ingredients to the wet ingredients and stir to combine.

To make a two-colored, layered mochi: Divide the batter into two equal parts. In one bowl, add ¼ teaspoon red food coloring and mix to thoroughly incorporate the food coloring. Pour the mixture into the prepared pan. Cover the pan with foil and bake for 20 minutes. Remove from the oven and pour the remaining batter (uncolored) over the first layer. Cover with foil and bake for 40 minutes.

To make a single-colored mochi: Add ½ teaspoon red food coloring and mix to thoroughly incorporate the food coloring. Pour the mixture into the prepared pan. Cover the pan with foil and bake for 1 hour.

Bake until the edges begin to pull away from the pan. The edges may appear slightly hard and over-baked, while the center of the dish will appear moist. Remove from the oven and allow to cool completely.

When the mochi is cooled, sprinkle your work surface with potato starch or kinako. Use a plastic knife to cut the mochi into small rectangles. Roll in potato starch to cover all sides, dusting off any excess.

Store in an airtight container in the refrigerator for up to 5 days. Microwave cold mochi for 10 seconds to soften before serving.