Combine the first 5 ingredients (through salt) in a food processor. Cover and process until very smooth. If desired, add food color, using as much as needed, to reach desired color. Transfer mixture into a 1-quart freezer container or loaf pan lined with plastic wrap. Cover and freeze 4 hours or overnight or until firm. Remove from container or pan. Slice and serve topped with toasted coconut and poppy seeds, if desired.