Source: Blue Willow Restaurant, Tucson, Arizona

Serves 12 to 15

2 cups all-purpose flour (448 grams)
2 cups granulated sugar (448 grams)
1/4 teaspoon salt (1 gram)
4 ounces unsweetened chocolate (112 grams)
1 cup water (240 ml)
1/2 cup butter (112 grams)
1 cup sour cream, at room temperature (240 ml)
1 teaspoon vanilla extract (5 ml)
1 1/2 teaspoons baking soda (6 grams)
2 beaten eggs

Chocolate Sour Cream Frosting
2 cups confectioners' sugar (450 grams)
Pinch of salt
1 1/2 teaspoons vanilla extract (8 ml)
1/3 cup milk (80 ml)
4 ounces unsweetened chocolate (112 grams)
1/3 cup melted butter (80 ml)

Grease or line two 9-inch (23 cm) cake pans or one 9 x 13-inch (23 X 33 cm) pan. Preheat oven to 350 degrees F (175 degrees C).

In mixer, combine flour, sugar and salt.

Melt chocolate with butter and water Add melted chocolate mixture to flour mixture and mix lightly. Add sour cream, vanilla extract, baking soda and eggs and mix well for 2 minutes.

Pour batter into pans and bake until wooden pick inserted in middle comes out clean. Bake for 30 minutes. Cool on rack 10 minutes and unmold cake to cake rack to cool completely before frosting.

To make frosting: In mixer, combine confectioners' sugar, salt, vanilla extract and milk. Melt the unsweetened chocolate and add to confectioners' sugar mixture. Slowly add melted butter and beat to spreading consistency.

Ice cake using about 1/2 cup (220 ml) of icing between layers.