Step by step method

1. Preheat oven to 180 degrees Celsius (150 degrees fan-forced).
   Grease 1 x 18 cm loose bottomed cake tins.
2. Combine all the cake ingredients in the bowl of an electric mixer (fitted with the paddle attachment).
3. Beat on low speed until combined. Increase the speed to high and beat the mixture until it is just smooth.
4. Spoon mixture into the baking tin and bake for 1 hour 5 minutes or until a cake tester inserted in center comes out clean.
5. Allow to cool in cake tin on a wire rack for 5 minutes. Turn out onto the wire rack and cool completely. Trim the top off and slice the cake in half so you have 2 layers.
6. To make the mousse, whip half the cream to soft peaks then refrigerate until needed. Heat the rest of the cream to just below boiling point, then pour over the chopped chocolate. Allow to stand for a few minutes then stir until smooth. Set aside.
7. Whip egg yolks on high speed in a stand mixer until light and stiff. Place the sugar, water and matcha powder in a small saucepan and stir until the sugar has dissolved then bring to the boil. Simmer until the syrup reaches 120 degrees Celsius on a sugar thermometer.
8. Start whipping the egg yolks again on low speed and gradually add the hot sugar syrup down the side of the bowl. Whip until the mixture has doubled in volume and is body temperature.
9. Test the temperature of the ganache (it should also be body temperature), then fold the ganache into the whipped yolks. Fold in the whipped cream in 2 batches.
10. To assemble, fill the bottom of a large silicone Bundt mould or standard 25cm silicone cake mould with 1/3 of the chocolate mousse. Use a spoon to fill all the ridges of the mould with chocolate mousse. If you are using a bundt mould, use a cookie cutter to cut out the center of the cake slices to fit the center of the bundt mould.
11. Press the cake layer into the bottom, top with another 1/3 of the chocolate mousse, then the remaining cake layer and fill with mousse. Freeze the cake for at least 4 hours or overnight.
12. To make the mirror glaze, place the water, sugar and condensed milk in a saucepan and bring to the boil. Remove from the heat and add the bloomed gelatin.
13. Stir until dissolved then add the chopped chocolate and stir until melted. Set the bowl over an ice bowl and whisk gently (not vigorously as you don’t want to make bubbles) until the glaze thickens and reaches 26 degrees Celsius.
14. Tint the glaze matcha green.
15. To assemble the cake, remove from the freezer and unmould (use a hair dryer on low setting to release it if necessary). Place the cake on a cooling rack with a baking sheet underneath.
16. Pour the glaze over the top of the cake in one go, making sure it drips down the sides evenly.
    
    Store in the fridge until ready to serve.

17. Process Shot 1

18. Process Shot 2

19. Process Shot 3