First cream the butter , cream cheese, ground pistachio and powdered sugar till creamy and light.
Add eggs,vanilla extract, green colour and mix nicely.
Now add maida, baking powder, salt and chopped pistachio. Mix nicely.
Pour into prepared pan and sprinkle some pistachio (for decoration) on top.
Bake at pre heated oven at 160°C for 30-35 mins
When cool drizzle with white chocolate.. Enjoy .!!