Preheat oven to 350 degrees. Grind the pistachios in a small blender. I used my Cuisinart 4-cup food processor.
Combine all the dry ingredients in a medium sized bowl.
Zest the lemon, you should have roughly 2 tsp.
Whip butter in a large bowl until creamy.
Add sugar and blend until creamed, about 5 minutes.
Then add eggs one at a time.
Now add vanilla and mix well.
Now alternate between the dry ingredients and milk starting and ending with the dry in 2 batches. Adding some flour. DO NOT OVER MIX!
Now add milk. Alternate until done. DO NOT OVER MIX.
Add lemon zest.
Add 2 drops of green food color, more if you wish. Combine.
Pour the batter into a round 9" springform pan and into the oven for 40-45 minutes.
Once cool, dislodge cake and place it on a cake stand.
Now make the whipped cream topping. Add all the contents of the whipped cream in a large bowl.
Mix until light and fluffy, DO NOT OVER MIX otherwise you'll end up with butter.
Whipped topping is done. Top over cake and serve.