1. Read the ingredients and method on the cake mix box and follow.
2. Bake the cake on a rectangular baking sheet lined with baking paper. Let the cake cool down before cutting it into circles that fit into the base of the glass.
3. In a pot, add sugar, water, coffee, and vanilla and bring to a boil and let it simmer for 10 minutes until slightly reduced. Turn off the heat and put it aside.
4. To make the white chocolate custard, add milk, sugar, and custard powder in a pot and stir to combine. Cook it over low flame until thickens. Place the hot custard into a bowl with white chocolate chunks and mix to combine. Line the top with a glad wrap to avoid a layer forming and let it cool.
5. To make the chocolate pudding, add milk, cocoa powder, sugar, and agar-agar powder in a pot and stir to combine. Cook it over low flame until it thickens. Place the mixture into a mold and let it cool and harden before cutting it into squares.
6. To make whipped cream, whip up whipping cream with sugar in a stand mixer until stiff peak.
7. Once you have prepared all, it’s time to assemble! Line the bottom of the glass with a piece of cake and drizzle or brush the coffee syrup. Then spread some white chocolate custard and for some crunch add some crushed cookies followed by the chocolate pudding, repeat for at least two layers before topping with whipped cream and grated chocolate. There you have it your delicious Chocolate Trifle.