Passover Chocolate Genoise & Buttercream Roll
This makes a very decadent cake with an exceptionally pretty presentation. The recipe looks complicated but it is not – it is simply three elements: a rich chocolate cake base, followed by a fluffy chocolate buttercream, and finished off with melted chocolate glaze. Can be made ahead and frozen or refrigerated until needed. Since the eggs are not separated in this recipe, you need a heavy-duty electric stand mixer such as a Kitchen Aid to achieve the most volume from the eggs.Serves 8-10
8 large eggs, warmed
3/4 cup sugar
1/4 cup matzoh cake meal
1/3 cup potato starch, not packed
1/4 cup cocoa, measured then sifted
1 tablespoon Passover vanilla sugar
1/4 teaspoon salt
3 tablespoons melted, unsalted Passover margarine or oil
Chocolate Buttercream Filling:
1/2 cup cocoa, measured, then sifted
1 cup unsalted Passover margarine, softened
2-3 cups Passover confectioner’s sugar
2-4 tablespoons warm water (brewed coffee or cola)
1 cup (4 ounces) semi-sweet chocolate chips
Semi-sweet chocolate shavings, or slivered, toasted almonds
Passover Confectioners’ sugar for dusting
Warm eggs (still in shells – do not open) by placing in a bowl and covering with very hot water for 1-2 minutes water should be hot but not so hot as to crack eggs open and cook them but hot enough to warm them up. Do not leave eggs in water longer than 1-2 minutes). This is the most important step. Do not omit it. Heat mixing bowl by filling with very hot water and then dry completely. Place eggs in an electric mixing bowl and, using the wire whip or whisk, mix on slow speed just to break up eggs. Then increase speed to high and beat ten minutes, dusting in the sugar gradually, as eggs are being whipped. After ten to twelve minutes, batter should be extremely voluminous.
In a small bowl, sift together cake meal, potato starch, cocoa, Passover vanilla sugar and salt.
Gently transfer batter into a very large mixing bowl. Dust in dry ingredients in small increments, gently folding after each addition. Drizzle in unsalted margarine or oil. Taking care not to deflate the mixture unduly (some deflation is impossible to avoid).
Filling: Using the whisk or whip attachment of an electric mixer, cream the margarine with the cocoa and most of the confectioners’ sugar on slow speed. Increase speed to high, stopping occasionally to scrape down bowl, and whip to make a fluffy frosting, adding in a couple of tablespoons of water (or coffee or cola) as required to achieve proper consistency. Buttercream should be whipped about 2-4 minutes.
Chocolate Glaze: Melt chocolate chips in the microwave (high 2-3 minutes).
Stir chocolate to make smooth.
Preheat oven to 350 F. Generously grease a baking or jelly roll sheet that measures about 11 by 17 inches similar sized baking pans – 10 by 15 inches, for example, are also fine). Line with parchment paper. (If you cannot find parchment paper for Passover, line sheet with aluminium foil and grease with unsalted margarine) Generously grease the parchment paper (this will help release cake later).
Pour batter into prepared pan. Bake 35-40 minutes until cake is set in centre or until cake seems just firm when lightly touched. Cool about 8 minutes then remove cake from baking pan (still with parchment paper attached). Using the parchment paper as an aid, roll up cake into a jellyroll or log. Wrap log in a new sheet of parchment paper and wrap in a clean, kitchen towel. Let cake rest this way about 20-30 minutes to allow cake to set or retain log shape. (It will be filled and re-rolled).
To assemble: Gently unroll cake and using a metal spatula, spread on chocolate buttercream. Re-roll cake into a log. Trip ends (about a 1/2 inch on each end to make neat). Wrap snugly in parchment paper and place in freezer while making chocolate glaze. Before glazing, let cake warm up to almost room temperature.
Spread glaze over chilled cake (using a pastry brush or small metal spatula). Coat as evenly as possible. (If cake is too cold, chocolate will set very quickly and be hard to spread – but it will still be fine). Garnish with chocolate shavings and a dusting of Passover confectioners’ sugar or with toasted slivered almonds (and confectioners’ sugar, optional).