In a medium size pot, add milk, condensed milk, cinnamon powder, nutmeg, cardamom powder and vanilla essence. Stir the mixture and bring to a boil on high heat. Stir in condensed milk and heavy cream, allow to simmer for an additional 5 minutes and keep on the side.
Cut the croissant into 1-inch-thick chunks. Place in a baking sheet lined with parchment paper and bake for about 6 to 8 minutes, until they have slightly browned and crisped up.
Grease the base of a 9 x 12-inch ovenproof baking dish with butter. Place half the quantity of croissants on the base, top with half the quantity of hazelnuts, almond flakes, raisons, desiccated coconut and pistachios. Top with the rest of the croissant and the toppings.
Gently pour the milk mixture over the pastry that is just barely emerging from it. Bake in the oven for about 20 to 25 minutes, until the surface has slightly toasted and has a golden-brown colour. Allow to rest for 5 to 10 minutes before serving.