Preheat oven to 160°C fan bake. Line a metal slice tin (approximately 18cm x 28cm) with baking paper.
Place Tararua Butter and dark chocolate in a large saucepan and cook, stirring, over a gentle heat until butter and chocolate are just melted.
Remove from heat and stir in Chelsea Caster Sugar, then sift in Edmonds Standard Grade Flour, cocoa powder and Edmonds Baking Powder. Mix until combined. Whisk eggs with a fork, then add to the mixture with vanilla extract. Mix well. Stir in milk chocolate and white chocolate.
Pour mixture into prepared tin. Bake in the middle of the oven for 30-35 minutes. Remove when the edges of the brownie are firm and it doesn’t wobble in the middle. Cool completely in tin before cutting into 2cm cubes.
Mix Edmonds Custard Powder, Chelsea Caster Sugar and 1/3 cup (80ml) Meadow Fresh Original Milk together in a medium-large saucepan until well combined. Stir remaining 2 2/3 cups (670ml) Meadow Fresh Original Milk into the custard mixture.
Heat to boiling, then simmer, stirring constantly, for about 5 minutes, or until custard has thickened. Remove from heat and whisk in dark chocolate until melted and smooth.
Place a layer of baking paper or cling film on the surface of the custard and allow to cool to room temperature.
Once brownie and custard have cooled and you are ready to assemble the trifle, place cream, Chelsea Icing Sugar and vanilla in a large bowl. Beat with an electric mixer until softly whipped.
ASSEMBLE & DECORATE
Layer half of the brownie cubes in the base of a large trifle bowl. Top with half of the custard and half of the cream. Add a second layer of brownie, custard and cream.
Tip: If custard has thickened too much on cooling, whisk in a little milk to thin it out and make it easier to layer up.
Decorate trifle with your favourite chocolates. Refrigerate for at least 2 hours (or up to 24 hours) before serving. Stars/candles can be added just before serving, if using.