The Copper Topper Cascade Mountain Cake


Preparation info

  • Difficulty


  • Serves:


Appears in

Rose's Celebrations

Rose's Celebrations

By Rose Levy Beranbaum

Published 1992

  • About

C-a-r-a-m-e-l. The very sound of the word, not to mention the tantalizing aroma of burnt sugar, makes me long for it, so I created this cake with a soft, very moist crumb, filled and frosted with creamy caramel buttercream and topped with a crunch of caramel nut brittle.

The cake was actually inspired by a cookie I heard about but have never tasted, from the Cascade Mountains in the state of Washington. Supposedly it was called “copper topper” because of its copper-colored caramel topping.

To honor the spirit of the mountains, I chose towering biscuit de Savoie cake layers (a butterless génoise) from the French Savoie because the cake can be made at high altitude since it has no chemical leavening. The brittle, broken into jagged pieces and inserted into the buttercream on top of the cake, is meant to resemble the mountain peaks. Store-bought peanut brittle, broken into pieces, can be used in its place.

This cake is for the caramel lover. It’s even more delicious than it looks.

FINISHED HEIGHT: to 4 inches

room temperature volume ounces/pounds grams
Biscuit de Savoie
8 large eggs, separated yolks 4.5 fluid ounces 5.25 ounces 150 grams
whites 1 liquid cup 8.5 ounces 240 grams
superfine sugar, divided 1 cup 7 ounces 200 grams
pure vanilla extract teaspoons
warm water 1 tablespoon
sifted cake flour 1 cup + 2 tablespoons (sifted into the cup and leveled off) 4 ounces 113 grams
cornstarch ½ cup + 1 tablespoon (lightly spooned into the cup) 2.25 ounces 66 grams
cream of tartar 1 teaspoon 3 grams
sugar ¾ cup + 2 tablespoons 6 ounces 175 grams
water liquid cups
almond-flavored liqueur 3 fluid ounces (6 tablespoons)
room temperature volume ounces/pounds grams
Caramel Silk Buttercream CRÈME ANGLAISE
milk 1 liquid cup
1 large vanilla bean, split lengthwise, or ½ large Tahitian vanilla bean, split*
sugar ½ cup 3.5 ounces 100 grams
water 2 tablespoons
5 large egg yolks 3 fluid ounces 3.25 ounces 93 grams
sugar cup + 2 tablespoons 3.25 ounces 92 grams
water 2 tablespoons
2 large egg whites ¼ liquid cup 2 ounces 60 grams
cream of tartar ¼ teaspoon
unsalted butter 2 cups 1 pound 454 grams
Copper Candy Topping
sliced unblanched almonds (peels on) ½ cup 5.25 ounces 85 grams
sugar 1 cup 7 ounces 200 grams
water ¼ liquid cup

*A vanilla bean offers the most delicious flavor, but if not available, replace the bean with 1 teaspoon vanilla extract, added to the cooled crème anglaise.

KEEPS: The biscuit (without syrup) can be stored 2 days at room temperature, 5 days refrigerated and 2 months frozen.


Biscuit de Savoie

In a large mixing bowl, preferably with the whisk beater of a heavy-duty mixer, beat the yolks and cup of the sugar on high speed for 5 minutes or until the mixture is very thick and ribbons when dropped from the beater. Lower the speed and beat in the vanilla and water. Increase to high speed and beat for 30 seconds or until the mixture thickens again.

Stir together the flour and cornstarch. Sift over the yolk mixture without mixing in and set aside.

In another large mixing bowl, preferably with the whisk beater, beat the whites until foamy. Add the cream of tartar and beat until soft peaks form when the beater is raised. Gradually beat in the remaining cup of sugar and beat until stiff peaks form when the beater is raised slowly. Add one third of the whites to the yolk mixture and with a large balloon whisk, skimmer or rubber spatula fold until incorporated. Gently fold in the remaining whites.

Pour into the prepared pans. (They will be almost half full.) Bake for 25 minutes or until a cake tester inserted in the center comes out clean. Loosen the sides with a small metal spatula and unmold at once onto lightly greased racks; then reinvert to cool. The firm upper crust prevents falling and results in a light texture.

When ready to complete the cake, remove the crust with a long serrated knife by scraping it lightly across the top and bottom of each layer.


In a small saucepan with a tight-fitting lid, bring the sugar and water to a rolling boil, stirring constantly. Cover immediately, remove from the heat and cool. Transfer to a liquid measuring cup and stir in the liqueur. If some of the syrup has evaporated, add enough water to equal 2 cups.

Sprinkle the syrup evenly over the tops and bottoms of the cake layers.* Cover them with plastic wrap while you make the buttercream.

*After syruping, a biscuit layer becomes fragile and more prone to splitting when moved. Use a cardboard round or removable bottom of a pan to support it.

Caramel Silk Buttercream

Have ready a sieve suspended over a bowl near the range.

In a small saucepan, scald the milk and vanilla bean. Remove from the heat and keep warm.

Bring just to the boiling point (small bubbles will begin to appear around the edges).

To Make the Crème Anglaise

In a medium-size heavy pan, combine the ½ cup of sugar and the 2 tablespoons of water and stir until the sugar is fully moistened. Bring to a boil, stirring constantly. Cook without stirring until deep amber (360°F.). Immediately remove from the heat and slowly pour in the hot milk (reserving the vanilla bean). Return to low heat and cook, stirring, until the caramel is totally dissolved.

In a medium-size heavy noncorrodible saucepan, place the yolks, and gradually add the caramel mixture to them, stirring constantly with a wooden spoon. Cook over medium-low heat, stirring constantly, until just below the boiling point. The mixture will start to steam slightly and an accurate thermometer will register 170°F to 180°F. Immediately strain through the sieve, scraping up any of the mixture clinging to the bottom of the pan.

Scrape the seeds from the vanilla bean into the custard, and cool to room temperature. (To speed cooling, put the bowl in another bowl or a sink partially filled with ice water.) Cover and refrigerate until ready to complete the buttercream, or up to 5 days.

The Cordon Rose candy thermometer is available through Dean & DeLuca (800-227-7714).

To Make the Italian Meringue

Have ready a heatproof glass measure near the range.

In a small heavy saucepan (preferably with a nonstick lining), combine the cup of sugar and the 2 tablespoons of water and stir until the sugar is fully moistened. Heat over medium heat, stirring constantly, until the sugar dissolves and the mixture is bubbling. Stop stirring and reduce the heat to low. (If using an electric range, remove from the heat.)

In a mixing bowl, preferably with the whisk beater of a heavy-duty stand mixer, beat the egg whites until foamy. Add the cream of tartar and beat until soft peaks form when the beater is raised. Gradually beat in the remaining 2 tablespoons of sugar and beat until stiff peaks form when the beater is raised slowly.

Increase the heat under the syrup and boil until an accurate thermometer registers 248°F. to 250°F. (the firm-ball stage). Immediately transfer the syrup to the glass measure to stop the cooking.

If using a hand-held electric mixer, beat the syrup into the egg whites in a steady stream. Don’t allow any syrup to fall on the beaters or they will spin it onto the sides of the bowl. If using a stand mixer, pour a small amount of syrup over the egg whites with the mixer off; then immediately beat at high speed for 5 seconds. Stop the mixer and add a larger amount of syrup. Beat at high speed for 5 seconds. Continue with the remaining syrup. For the last addition, use a rubber scraper to remove the syrup clinging to the glass measure. Lower the speed to medium and continue beating until completely cool, about 2 minutes.

Place the butter in a large mixing bowl and, preferably with the whisk beater, beat on medium speed for 30 seconds or until creamy. Gradually beat in the crème anglaise until smooth. Add the Italian meringue and beat until just incorporated. If the mixture looks curdled instead of smooth, it is too cold. Allow it to sit at room temperature to warm to 70°F. before continuing to beat. Or place the bowl in a hot water bath very briefly until the buttercream around the edge of the bowl just starts to melt. Remove at once and beat until smooth. Place in an airtight container. The butter- cream becomes slightly spongy on standing. Rebeat before using.*

*Do not rebeat chilled buttercream until it has reached room temperature or it may curdle.

Copper Candy Topping

On a lightly greased baking sheet, spread the almonds in a single layer. Set aside.

In a small heavy saucepan, combine the sugar and water and stir until the sugar is completely moistened. Bring the mixture to a boil over medium heat, stirring constantly until the sugar is dissolved. Increase the heat to medium high and boil undisturbed until the sugar begins to caramelize. It will begin to look like dark corn syrup and take on the characteristic smell of burnt sugar. (The temperature should be 370°F.) Immediately pour the caramel evenly over the nuts, covering as much of the nuts as possible. Allow the caramel to harden completely, 15 to 20 minutes. Remove it from the sheet and break it into pieces.

Assembling the Cake

Spread a little of the buttercream on a cake plate or 9-inch cardboard round and place a cake layer on top. Sandwich the cake layers with ¾ cup of the buttercream between each layer and frost the top and sides with the remaining buttercream. The cake will be about 3¾ to 4 inches high.

Arrange the Copper-Candy Topping on the cake top. (If you are planning to refrigerate or freeze the frosted cake, add the candy topping only after removing it from the refrigerator as it will become sticky if refrigerated.)

Serve the cake at room temperature or lightly chilled. Make sure that each serving contains a few pieces of the caramel nut topping. If the pieces become detached from the frosting, lay them decoratively on top of the cake.

KEEPS: 3 weeks at room temperature (if the humidity is low) in an airtight container.