Pre-heat the oven to 175ºC (350ºF). Line a muffin tin with cupcake cases. Melt the butter and then stir in the saffron. Set to one side.
Whisk the egg and sugar together until nice and fluffy. Add the butter/saffron and milk and stir to combine.
In a separate bowl, combine the flour and baking powder and stir into the wet ingredients.
Lastly, stir through the cranberries until evenly dispersed. Split evenly between eight cupcakes cases and bake for around 16-18 minutes, just until an inserted skewer comes out clean. Let the cupcakes cool completely.
For the frosting: beat the cream cheese together with the vanilla sugar and icing sugar. I used less icing sugar than normal which means that the frosting is less thick. If need be, pop the frosting into the fridge for 30 minutes to harden slightly.
Spread over the top of each cupcake (or pipe if you prefer) and sprinkle a few chopped pistachios and cranberries (optional). Enjoy!