Thai Steamed Coconut-Pandan Cake (Khanom Chan)

Name: Thai Steamed Coconut-Pandan Cake (Khanom Chan)
Cuisine: Asian, Thai
Ingredients: 1 bunch (4 oz.) frozen pandan leaves, thawed and cut into 1-inch pieces; Nonstick cooking spray; 1⁄2 cup sticky rice flour (2 ¾ oz.); 1⁄2 cup tapioca starch (2 1/8 oz.); 1 1⁄2 cups arrowroot starch (6 ¼ oz.); 1 1⁄2 cups firmly packed coconut palm sugar (about 1 ½ lb.); Two 13.5-ounce cans of coconut milk (32 oz.); 10-12 drops green food coloring (optional); 1⁄2 cup chilled jasmine-scented white tea, or water