In a mixing bowl, combine the glutinous rice flour, cornstarch, granulated sugar, passion fruit pulp, and milk. Mix the ingredients thoroughly until well combined.

Pour the mixture into a heat-resistant container and cover it with plastic wrap. Use a toothpick to poke a few holes in the plastic wrap to allow steam to escape during steaming.

Steam the mochi mixture for 15 minutes over boiling water.

Once the mixture is steamed, remove it from the steamer and carefully add 15g of butter. Using a spatula, gently press down on the butter and drag it back and forth across the surface of the mochi mixture to help it melt evenly.

Allow the mixture to cool to room temperature, similar to the process used in the watermelon mochi recipe. Once cooled, put on gloves to prevent sticking, and start stretching and pulling the mochi mixture repeatedly. Stretch it for about 5 minutes until it becomes smooth and elastic. This step is crucial for developing the desired soft and chewy texture of the mochi.

Sprinkle a layer of cooked glutinous rice flour on a clean surface or board to prevent sticking. Transfer the mochi mixture onto the floured surface.

Roll the mixture into a long strip using your hands. Then, use a scraper or knife to cut the strip into small, bite-sized pieces.

Once cut, your passion fruit mochi is ready to be enjoyed! Serve immediately or store in an airtight container for later indulgence.