Difficulty Rating: Hard
Blum's restaurant is in only San Francisco now, but it used to also be at Stanford Shopping Center near Palo Alto, California. In the 1960's and 70's, it was a place of ice-cream wonder and sugar-sprinkled joy. You walked in, and the whole thing was a soft pink and white. There were murals on the wall of stylized cartoon ladies having lunch as well as of cartooned sundaes and parfaits. There were white marble tables and white iron garden chairs with pink padding to sit on. It was part bakery, part eatery and part creamery. And to a 6 year-old, it was heaven on earth.
My mom used to take us there every week when she was pregnant with my brother Jim. That was back when women were only aloud to gain 19 pounds in 9 months. Lord! So after she weighed in at the Ob-Gyn, she would rush Sarah and I over to Blum's. There she would sigh with relief while eating a congratulatory "Coffiesta Sundae" or a piece of "Coffee Crunch Cake". The key is the "crunch", which made both desserts unique. It's the same thing as "seafoam candy" (at Marini's in Santa Cruz) without the chocolate coating. This is the real thing...found on Epicurean.com.
Note: If you want a short-cut, bake a mix cake (Duncan Hines Yellow Butter Cake)and just concentrate on making the Coffee Crunch instead of a scratch-cake. I personally have used a cake-mix many times as well as Martha Stewart's Old Fashioned Yellow Cake recipe. But this "genoise" recipe is very light and authentic! A bit tricky, but warm the eggs, before you crack 'em, in a bowl of very warm water first and you'll be fine.
Note:The key to anything made with egg whites is to always have the eggs at room temperature.
1 1/4 C cake flour, sifted
1 1/2 C sugar
1/2 t salt
6 egg yolks
1/4 C water
1 C large egg whites
1 t cream of tartar
1 t vanilla
1 T fresh lemon juice
1 t grated lemon zest
Coffee Crunch (Seafoam):
Unflavored vegetable oil
1 T sifted baking soda, sifted
1/4 C strong brewed coffee ( or 1 t instant espresso mixed with 1/4 C warm water)
1 1/2 C sugar
1/4 C light corn syrup
Note: For accuracy, always grease measuring cups or spoons before measuring corn syrup)
2 C heavy cream
2 T sugar
2 t vanilla
Note: when whipping cream have the cream and the bowl as cold as possible. Stainless steel bowls are the best conductors of cold temperatures.
For the cake: Adjust rack to lower third of the oven. Preheat oven to 350 degrees. sift flour, 3/4 C sugar and salt onto a sheet of wax paper or another bowl, set aside.
Using an electric mixer, beat egg yolks with 1/4 C sugar until thick and pale yellow. Add water and beat until thickened, about 4 minutes. Whisk egg whites in bowl of a heavy-duty mixer, (I have a hand mixer--works fine)just until frothy. Add cream of tartar; whisk until soft peaks form. Add remaining w/2 C sugar in a steady stream,whisking until thicker, stiffer, glossy peaks form, --about 2-3 minutes. Whisk in vanilla, lemon juice and lemon zest. Pour yolk mixture over whites. Fold together with rubber spatula. Repeat two more times just until ingredients are incorporated. Gently pour batter into an ungreased 10-inch round tube pan. Level top with a rubber spatula.
Bake for 50-55 minutes, or until top springs back slightly when touched with a finger. Invert pan over a long-necked bottle to cool for about 45 minutes. To remove cake from pan, slip a flexible metal spatula down one side of pan; slowly trace perimeter to release the cake. When sides are free, push up on bottom to release cake. Tilt cake,with removable bottom still attached, and gently tap bottom against counter to loosen cake. Rotate cake, tapping a few more times until it appears free. You can also run a knife along the edges, but make sure the cake is absolutely cool before doing this! Put a plate or a rack on the top of the cake pan, and invert, so that cake lands on plate or rack when it falls out. Remove bottom of pan by sliding a knife around the edge, but only if needed. It may just fall off!
Coffee Crunch Topping: Generously oil a large baking sheet; sift baking soda onto a sheet of wax paper or plate; set nearby. Combine coffee, sugar and corn syrup in a heavy, 4qt. saucepan. Place over med-low hear, stirring occasionally, until sugar dissolves. When mixture is clear and begins to boil, increase heat to med-high; cook until mixture reaches 290 degrees on a candy thermometer. Toward end of cooking (around 270-280 degrees), the candy should be the color of real caramel (like on candied apples). Stir constantly at this point to prevent mixture from scorching and becoming too foamy. When it's just starting to scorch a bit or smell a little burned, remove from heat and immediately stir in presifted baking soda. You only have to give it 2-3 stirs. Mixture will foam up fiercely--it will balloon up almost to the top of the pan. That's how you know it's a successful batch--- it billows! While still frothing, pour out onto an oiled baking sheet. Do not spread. Let cool, undisturbed for at least 1 hour. Crush into small pieces by placing between two pieces of wax paper or plastic wrap and roll with a rolling pin or tap with a cooking knife.
Note: If it only ballooned enough to fill the saucepan half full--the candy wasn't hot enough. It has to be almost burnt. Try again. Practice makes perfect!
For the Frosting: Combine cream, sugar and vanilla; beat until cream holds sturdy peaks.
To Assemble: Slice cooled cake into 3 equal layers using a serrated knife. Spread whipped cream between each layer, carefully stacking layers as you go. Spread remaining whipped cream over top and sides of cake. Refrigerate. Just before serving generously sprinkle top and sides with coffee crunch. The cake should be fine for up to 1 hour after the crunch is applied--but after that the candy will melt completely into the whipping cream. Sort of like Cinderella and the clock striking midnight!