Preheat oven to 325* for coated or dark pans 9 x 13 or 350* for glass or pans not coated. Spray or use butter to coat pan & sprinkle flour, sift remaining powder in trash, set pan aside.
Mix French Vanilla cake mix according to box with the following ingredients: eggs, water, & oil. Once Blended add 1 box of pistachio pudding mix, blend until smooth. Also, for a more vibrant green color add a few drops of green food coloring.
Bake in oven for 26-29 minutes according to box. While that's baking, mix cream cheese (blends best at room temp.), 1/2 cup milk, & 1 tsp vanilla until smooth. Then add one box of pistachio pudding mix and an additional 1/2 cup of milk, blending well... then lastly blend 1 whole tub of cool whip to the mix and refrigerate.
When the cake is cool... Use a frosting spatula to slip around the outer edging of the cake to make sure its not sticking to the pan. Then take a cookie sheet, place on top of cake, hold tightly together and flip quickly, set flat on table, tap the bottom of cake pan a few times, lift cake pan off the now upside down cake, take a cake knife or any long knife and cut evenly down the center splitting the cake into 2 sections. Once separated flip and place the bottom half of the cake back in the pan or on a tray.
Remove pistachio filling from fridge, stir a few times to make it easier to spread on the bottom layer of the cake... once all of the pistachio filling has been spooned on the bottom layer of the cake... smooth over to make it evenly across the entire cake, then flip and place the top half of the cake back on the bottom.
Lastly, take the remaining 1 cup of milk and pistachio pudding mix and blend well. Now add the remaining 8oz tub of cool whip and blend. Finally, frost the top layer of the cake. Ready to serve, Enjoy!
TIP: For a creamier topping make the pudding as the box tells you, then add an 8 oz tub of cool whip, blend well and add topping to cake. For an extra touch sprinkle almonds on top!