Pour milk into a heavy-bottom saucepan. Bring to a rolling boil over medium-high heat, stirring occasionally so the milk does not scorch on the bottom.

Reduce heat to low and simmer, stirring every few minutes and scraping the sides and bottom where cream collects. Cook until the milk reduces to about half its original volume, roughly 25 to 35 minutes depending on your pan and heat.

Stir in cardamom, sugar, and salt if using. Continue simmering on low until the milk thickens further and reduces to about one-quarter of the starting volume. The rabri should coat the back of a spoon and look creamy, not watery.

If using saffron, stir in the soaked threads and milk. Remove from heat and let cool completely at room temperature, then refrigerate until cold. For extra-smooth rabri, blend once in a blender and chill again.

Crumble each motichoor ladoo with your fingers into fine, even crumbs. Divide the crumbs among 6 small jars, pressing lightly to form an even layer on the bottom.

Spoon chilled rabri over the motichoor layer, filling each jar about three-quarters full.

Garnish with almond and pistachio slivers. Cover loosely and refrigerate 6 to 8 hours before serving so the layers set and the ladoos soften slightly.