Line the base of an air tight container with baking paper and set aside.
Place cake in a bowl and use your fingers to break and crumble it into fine crumbs.
Place 60 grams of white chocolate in a microwave safe bowl and pour 40 grams of thickened cream over the white chocolate.
Place the bowl of chocolate & cream in the microwave and heat for 20 seconds. Remove and give the mixture a really good stir.
If the chocolate has not completely melted, return the bowl to the microwave and heat again for a further 10 seconds. Give the mixture another good stir. All the chocolate should now be melted, if not repeat the process of heating for 10 seconds and stirring.
Once all the chocolate is melted, stir through 3 teaspoons of matcha powder.
Pour matcha ganache over cake crumbs and combine well with a spoon. Give the mixture a little taste, and add extra matcha powder to strengthen the favour if desired.
Roll cake mixture into balls. I aim for about 20g in size (if you're eyeballing it, they should be a little smaller than a golf ball).
Place cake balls into the container you prepared earlier, and seal with the lid and put in the fridge to chill for at least 1 hour.
When you're ready to start decorating, bring the cake pops out of the fridge and place on the bench so they can come to room temperature as you prepare the decorations.
Place 200g of white chocolate in a microwave safe bowl. Heat in the microwave at 20 second intervals, until completely melted (make sure you stir well after each zap to avoid burning the chocolate).
Stir shortening through the white chocolate to thin it slightly.
Give the cake ball a quick roll between your hands to make sure it's still round, then dip a lollipop stick into the melted chocolate and insert into the cake ball.
Place cake pops back into the container (make sure the lollipop sticks are sticking in the air, otherwise one side of the cake pop will have a flat base).
Transfer to the fridge for 10-15 minutes to allow the chocolate to set, so that the sticks are glued in place.
Meanwhile check the consistency of your dipping chocolate, if it has firmed up again reheat in the microwave for 5-10 seconds and stir well.
Optional, stir 1 teaspoon of matcha powder through the dipping chocolate. For details of how made this marbled effect, check out my notes below.
Remove cake pops from the fridge and dip into melted chocolate. Tap off excess chocolate and place onto tray lined with baking paper. Quickly scatter some sprinkles over the top before the chocolate sets.
Transfer decorated cake pops to the fridge and allow to completely set (minimum 1 hour).