Triple Layer Chocolate Truffle Cake

Directions

• Preheat oven to 350°F. Lightly grease 2 15×12″ jelly roll pans (check notes for 1 pan), then line them with parchment paper and set aside. In a medium saucepot over medium-low heat melt together the butter, 6oz (170g) of the bittersweet chocolate and the vanilla. Whisk until smooth and set aside.
• In another small saucepot, whisk the cocoa powder with the water and bring to a boil while whisking near constantly. Let cool for 5 minutes, then mix this and then creme fraiche into the melted chocolate mixture.
• In a large bowl beat together the eggs, egg yolks, sugar and brown sugar until light and frothy (about 5 minutes). Whisk in the chocolate mixture. Sift in the flour, baking soda, baking powder, salt and espresso powder (if using). Gently fold it in, being careful not to overmix. Evenly divide the batter between the pans and top with the remaining 4oz (113g) of bittersweet chocolate. Bake for 26-32 minutes, until the top springs back after being gently pressed. Let cool completely, then cover with plastic wrap and chill for at least an hour.
• In a double boiler (heatproof bowl over pot with boiling water) add the white chocolate and stir until melted. Heat the cream and butter (for the white ganache) in a separate small saucepot until bubbling. Once white chocolate is melted, remove from the double boiler and whisk in the hot cream. Cover with paper towels and let cool to room temperature.
• In another small saucepot (or the same one, cooled and washed out) add the cream (for the bittersweet ganache) and bring to a simmer. Add the bittersweet chocolate to a heat-safe bowl and pour the cream over. Let sit for 3 minutes, then whisk until smooth. Cover with paper towels and let cool to room temperature. Once both ganaches are cooled, cover with plastic and chill. The time you will want to chill them will vary; you want them to be thick but spreadable. Usually about 25-30 minutes for me.
• For the frosting, melt the bittersweet chocolate in a microwave-safe bowl in 30 second increments, stirring in between. Combine the sugar, corn syrup, cocoa powder and water in a saucepot and bring to a boil while whisking constantly. Remove and let cool completely. Cream the butter in a stand mixer (or by hand, or hand mixer) until light and creamy. Add the chocolate mixture, followed by the powdered sugar in small batches. Scrape down the sides, then beat again until smooth and fluffy.
• Cut each cake into 3 5×11″ rectangles and set aside. I would recommend cutting through the parchment too, so each piece is easier to move. Spread a small dollop of frosting onto your desired serving stand/plate, or a turntable with a cake board/parchment on it. Place one of the cake rectangles in the middle, then peel off the paper and top with 1/2 of the white ganache. Then another cake layer, and half of the bittersweet ganache. Top with another cake layer, then enough frosting to equal the height of a ganache layer. Repeat with the remaining ganache, and spread most of the remaining frosting over the top and sides using an offset spatula and/or bench scraper. Top with chocolate curls (if using), cover, and chill at least overnight.
• Slice into small bar-shaped pieces (it is very rich!) and enjoy! Keeps up to 1 week in the fridge, or 2 months in the freezer.