How to Make a Raindrop Cake Make a 3 Ingredient Raindrop Cake, also known as the Japanese Mizu Shingen Mochi, using Agar, sugar and spring water. Agar, simply put, is the vegan equivalent of gelatin - a seaweed gelling agent - that comes in sticks, powder, flakes, or premixed with sugar. Some say the Raindrop Cake tastes like flavored jello, then when eaten it dissolves quickly into water. I’ve found 2 really good tutorials and recipes for making a Raindrop Cake Learn from the 3 attemp