In a large pot, melt the butter over medium heat.
Add the vermicelli noodles and fry until light golden and fragrant, being careful not to burn them.
Add the cinnamon stick and whole cardamom pods, stir for a few seconds to release the aroma.
Pour in the milk and water, then bring to a gentle simmer.
Stir in the sugar and soaked sago pearls. Continue cooking over low heat, stirring frequently to prevent sticking.
Simmer for 20–30 minutes, until the sago is translucent and the mixture is creamy.
Add ground cinnamon, ground cardamom, and rose water or almond essence if using. Stir well.
Serve hot, garnished with nuts if desired.