Cook and stir milk, vanilla extract, and butter in a saucepan over medium heat until simmering. Remove mixture from heat before it comes to a boil.
Whisk eggs, sugar, and cornstarch together in a bowl until sugar dissolves.
Set saucepan back over low heat. Add egg mixture while constantly whisking, until custard thickens enough to coat the bottom of a spoon, 5 to 10 minutes.
Cool this and then transfer to a piping bag
Take a clean glass jar and place a piece of ras malai on the bottom. Cover it with custard and top it with dry fruits.
Repeat this process and fill the jar, garnish with dried rose petals and dry fruits