Prepare caramel custard as per package directions. Pour into silicon moulds and refrigerate. (I always add less milk than what is mentioned in the package)
In a bowl, add whipping cream and powdered sugar. Whip well until you get stiff peaks.
Pour melted and cooled white chocolate into it and mix gently until combined or beat on very low speed until just combined.
Gently fold in the thick cream into the it.
Keep the cream refrigerated for an hour for it to set a bit. (This step is optional, you can use it directly to assemble too)
To assemble, place the cake in the mini trifle cup at the bottom.
Drizzle mango juice all over the cake.
Add mango.
Pipe the white chocolate cream into it.
Repeat the layer once more.
Finally place the caramel custard on top.
Garnish it with mangoes and pistachios.