A semi-old picture that took me SUCH an obscenely long time to finish...

And here`s a recipe for cake:

1 package yellow cake mix (regular size)
1 package (3.4 ounces) instant pistachio pudding mix
4 large eggs
1 cup club soda
1/2 cup canola oil
1/2 cup chopped walnuts
ICING:
1 cup cold heavy whipping cream
3/4 cup cold 2% milk
1 package (3.4 ounces) instant pistachio pudding mix
2 teaspoons confectioners' sugar
1/2 cup chopped walnuts

In a large bowl, combine the cake mix, pudding mix, eggs, soda and oil; beat on low speed for 30 seconds. Beat on medium for 2 minutes. Stir in walnuts.
Pour into a greased and floured 10-in. fluted tube pan. Bake at 350° for 40-45 minutes or until a toothpick inserted in the center comes out clean. Cool for 10 minutes before removing from pan to a wire rack to cool completely.
In a large bowl, beat the cream, milk, pudding mix and confectioners' sugar on high until stiff peaks form. Frost cake. Sprinkle with walnuts. Refrigerate until serving.

Test Kitchen Tips
For perfect creamy icing, make sure that the heavy whipping cream is cold and that the thickest cream isn't left clinging to the carton. You need that fat to whip the cream properly.
This cake can also be made in a 13x9-in. baking dish. Bake until a toothpick inserted in the center comes out clean.
Nutrition Facts
1 slice: 482 calories, 28g fat (8g saturated fat), 99mg cholesterol, 555mg sodium, 53g carbohydrate (33g sugars, 1g fiber), 7g protein.