Passover Chocolate Genoise and Butter Cream Roll

"Looks complicated but it's not. A rich chocolate cake base, followed by a fluffy chocolate butter cream, 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 to get the most volume from the eggs." - Marcy Goldman.

Recipe Ingredients:

Genoise:
8 large eggs - warmed in shell (see below)
3/4 cup granulated sugar
1/4 cup matzoh cake meal
1/3 cup potato starch - loose
1/4 cup cocoa powder - measured then sifted
1 tablespoon Passover vanilla sugar
1/4 teaspoon salt
3 tablespoons melted, unsalted Passover margarine or oil

Butter cream:
1/2 cup cocoa powder - measured, then sifted
1 cup unsalted Passover margarine - softened
2 to 3 cups Passover confectioner's sugar
2 to 4 tablespoons warm water (or brewed coffee or cola)

Glaze:
1 cup (4-ounces) semisweet chocolate chips

Garnish:
Semisweet chocolate shavings or slivered toasted almonds
Passover confectioner's sugar for dusting

Cooking Directions:

1. Preheat oven to 350°F (175°C). Generously grease a baking or jelly roll sheet (about 11 x 7 inches). Line with parchment paper. If you cannot find parchment paper for Passover, line sheet with aluminum foil and grease with unsalted margarine. Generously grease parchment or foil.
2. Warm eggs (still in shells) by placing in a bowl and covering with hot (not boiling) water for 1 to 2 minutes. Heat mixing bowl by filling with hot water and then dry thoroughly. Place eggs in bowl. Using a wire whip or whisk attachment, mix on slow speed just to break up eggs. Increase speed to high and beat 10 minutes, dusting in the sugar gradually. After 10 to 12 minutes, batter should be quite high.
3. 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 too much.
4. Pour batter into prepared pan. Bake 35 to 40 minutes until cake is set in center or is firm to the touch. 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 jelly roll or log. Wrap log in a new sheet of parchment paper and wrap in a clean, kitchen towel. Let cake rest this way 20-30 minutes to allow it to retain log shape. (It will be filled and re-rolled).
5. Filling: Using the whisk or whip attachment, cream the margarine with the cocoa and most of the confectioner's sugar on low speed. Increase speed to high, stopping occasionally to scrape down bowl and whip to make a fluffy frosting, adding a couple of tablespoons of water (or coffee or cola) as required to achieve proper consistency. Butter cream should be whipped 2 to 4 minutes.
6. To assemble: Gently unroll cake and using a metal spatula, spread on chocolate butter cream. Re-roll into a log. Trim 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 close to room temperature.
7. Chocolate Glaze: Melt chocolate chips in the microwave (on HIGH 2 to 3 minutes). Stir chocolate to make smooth. Spread 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 confectioner's sugar or with toasted slivered almonds and confectioner's sugar.

Makes 8 to 10 servings.

Recipe from: The Baker Boulanger - Seasonal Table, by Marcy Goldman. Used with permission.