Combine water, sugar, cardamoms, and saffron in a saucepan. Cook over medium high heat until the sugar has dissolved. Remove from heat and set aside.

In a large cooking vessel, melt butter over medium heat. Add vermicelli and cook, making sure to stir often, until golden brown, up to 5 minutes. Add prepared sugar syrup and allow the vermicelli to soak up all of the liquid; Keep an eye on the vermicelli because it doesn’t take long for all of the syrup to be absorbed.

Serve warm, at room temperature, or cold. Garnish with crushed nuts.