Place pistachios in a large sauce pan, cover with water, bring to a boil and cook 2 minutes. Drain pistachios

Place drained pistachios in a food processor and blend until smooth This will take about 2 minutes, scraping prosessor sides a few times

Add butter and blend until smooth

Add 1 cup of the confectioner's sugar slowly in batches, blending, it will become very smooth

Beat cream to soft peaks, add vanilla and remaining 1 cup confectioner's sugar

Add a few spoon fulls of pistachio puree , beating in careful not to over beat. When cream is thickened fold in remaining pistacho puree to blend. I used natural un colored pistachios so to get the classic green color I added some green food.color

In a small bowl whisk together flour, cocoa powder, baking powder and salt

Seperate eggs, place whites in one large bowl and yolks in a seperste large bowl. Beat the egg whites intil foamy, gradually add 1/4 cup of the sugar and beat untuil stiff peaks form

Beat egg yolks, remaining sugar and vanilla until light and creamy, stir in flour/ cocoa mixture

Fold 1/3 cup egg white mixture into yolks, then fold temaining

Spread batter evenly in prepared pan. Bake 12 to 15 minutes until a toothpick comes out just clean

Cool 2 minutes on a wire rack. Meanwhile dust a clean kitchen towel with confectioner's sugar. Run a small knife around cake edges to loosten and invert cake onto towel

Carefully peel off parchment paper

Roll cake up in towel in long cylinder, cool on rack

Unroll cake and spread with some pistachio cream

Roll cake up using towel to help tightly roll. Place seam side down on a platter and frost with remaing pistacho cream, garnish with pistachios. Refrigerate at least 2 hours before slicing. Serve with whipped cream