Choose a ripe watermelon and cut it in half. Slice each half into strips and remove the flesh from the rind. You can also check out my recipe for Watermelon Popsicles to see how I scoop out the watermelon flesh.

Place the watermelon flesh into a blender and blend until smooth. I measure out 300g of watermelon juice for the mochi recipe, reserving the remaining juice for making Watermelon Popsicles.

Mixing the Ingredients: In a large bowl, combine glutinous rice flour, cornstarch, sugar, and watermelon juice. Mix well until fully combined.

Sift the mochi mixture once to ensure a smooth texture.

Cover the bowl with plastic wrap, poke a few holes with a toothpick, and microwave on high for 5 minutes.

After microwaving, add butter to the hot mochi mixture.

Allow the mochi mixture to cool to room temperature, then knead until the butter is evenly incorporated. Stretch it for approximately 5 minutes until it reaches a smooth and elastic consistency.

Transfer the mochi dough into a container lined with parchment paper. Use your hands to flatten the surface of the mochi dough.

Refrigerate the mochi dough for at least 3 hours, or until firm.

Once chilled, dust the watermelon mochi with cooked glutinous rice flour to prevent sticking.

Cut the watermelon mochi into strips, and then into bite-sized pieces.