Recipe(tried): McCall's Cooking School Perfect Chocolate Cake (1970's, 3 layers, whipped cream filling and chocolate frosting)

PERFECT CHOCOLATE CAKE

1 cup unsifted unsweetened cocoa powder
2 cups boiling water
2 3/4 cups sifted all-purpose flour
2 teaspoons baking soda
1/2 teaspoon baking powder
1/2 teaspoon salt
1 cup butter or margarine, softened
2 1/2 cups granulated sugar
4 large eggs
1 1/2 teaspoons vanilla extract
Whipped Cream Filling (recipe follows)
Chocolate Frosting (recipe follows)

Preheat oven to 350 degrees F. Grease well and lightly flour three (3) (9 x 1 1/2-inch) layer cake pans.

In medium-sized bowl, combine cocoa powder with 2 cups boiling water, mixing with wire whisk until smooth. Cool completely. Sift flour with baking soda, baking powder and salt.

In large bowl of electric mixer, at high speed, beat butter, sugar, eggs and vanilla until light (about 5 minutes), scraping bowl occasionally.

At low speed, beat in flour mixture (in fourths) alternately with cocoa mixture (in thirds), beginning and ending with flour mixture. Do not overbeat. Divide batter evenly into prepared cake pans; smooth top.

Bake 25 to 30 minutes or until surface springs back when gently pressed with fingertip. Cool in pans 10 minutes. Carefully loosen sides with spatula; remove from pans; cool completely on wire racks.

TO ASSEMBLE THE CAKE:
On plate, place a layer top side down; spread with half of whipped cream. Place second layer top side down; spread with rest of whipped cream. Place third layer top side up.

With spatula, frost sides first, covering Chocolate Frosting; frost top with remaining frosting, swirling decoratively.*

Refrigerate at least 1 hour before serving.

To cut, use a thin-edged sharp knife; slice with a sawing motion.

FROSTING

1 (6 oz.) pkg.semisweet chocolate pieces
1/2 cup light cream
1 cup butter
2 1/2 cups unsifted confectioners' sugar

In medium-sized saucepan, combine chocolate pieces, cream and butter; stir over medium heat until smooth.

Remove from heat. With whisk, blend in 2 1/2 cups confectioners' sugar.

In bowl set over ice, beat until frosting holds its shape.

FILLING

1 cup heavy whipping cream, chilled
1/4 cup unsifted confectioners' sugar
1 teaspoon vanilla extract)

Whip heavy cream with confectioners' sugar and vanilla; refrigerate.

*FROSTING TIPS:
- Brush crumbs from the top and side of each cake layer.
- Position 3 or 4 strips of waxed paper around the edge of the plate. Place cake on top of waxed paper.
- Spread sides of cake with a thin layer of frosting; add more frosting, using tip of spatula to create swirls. Spread remaining frosting over top of cake in large swirls.
- Pull paper gently from beneath cake.

Makes 1 (9-inch, 3-layer) cake, 12 servings
Source: McCalls' Cooking School, 1970's