Preheat the oven to 180 degrees and grease a 7 inch pan with oil/ butter.
Add the saffron to warm milk and keep aside.
In a bowl, whisk yogurt, sugar, and oil. Add the saffron milk and mix it in.
Add flour, pistachio powder, baking powder, and baking soda to the bowl and whisk everything just till you get a smooth batter. Do not over-mix the batter.
Transfer to the prepared pan and bake for 30-35 minutes or till a toothpick inserted comes out clean.
Let it cool and frost with the saffron buttercream
Garnish with slivered pistachios, rose petals, and saffron strands.