Combine the chocolate, cream, and butter in a heatproof bowl and heat in the microwave or over a double boiler until melted

Stir until completely combined, cover with cling wrap, and place in the fridge to chill for 1-2 hours or until completely firm

Line a baking tray with parchment paper

Divide the ganache into 8 portions and roll them into balls

Place the balls on the lined baking tray and refrigerate for 30 minutes or until firm

Combine the glutinous rice flour, sugar, cocoa powder, and cornstarch in a medium-sized microwave-safe bowl, and whisk to combine

Pour in the milk into the dry ingredients, and whisk until smooth

Cover the mochi mixture with cling wrap and microwave for 2 minutes on high

Uncover and stir

Then re-cover and microwave for another 2 minutes, the mochi dough should be semi-translucent

If the mochi is still slightly liquidy/milky re-cover it and microwave at 1-minute intervals until cooked through

Allow the mochi to cool enough to handle

Add the vegetable oil and using gloved or oiled hands knead until smooth

Prepare a baking tray lined with baking paper

Divide the mochi into 8 equal portions and place on the baking sheet.

Put the cocoa powder in a shallow bowl

Flatten a ball of mochi in your palms

Add a ball of chocolate ganache in the center and pull the sides of the mochi over it to enclose the ganache, pinch to close

Roll the assembled mochi in the cocoa powder

Repeat until all the mochi and ganache have been used