Chocolate Peanut Butter and Jelly Rolls - eggs

Method

• For the cake: Heat the oven to 375 degrees F. Line two 9 1/2-by-14-inch jelly-roll pans with parchment paper, leaving 1 inch of paper hanging over on all sides (this will help you lift the cakes out of the pan after baking).
• In the bowl of a stand mixer fitted with the whisk attachment, whip the yolks and 1 cup of the sugar on medium speed until the mixture is thick and fluffy, 3 to 4 minutes.
• Add the vanilla and mix for 1 minute.
• Scrape into a medium mixing bowl and set aside.
• Wash the stand mixer bowl and whisk very well (even the smallest amount of yolk will prevent the whites from whipping properly).
• Put the whites and salt in the mixer bowl whisk at medium speed until he whites become frothy.
• Slowly add the remaining 1/2 cup plus 2 tablespoons sugar.
• Increase the speed to high and whip until the whites become glossy and almost firm (the whites should not become dry).
• Remove the bowl from the mixer.
• Sift the cocoa over the egg yolk mixture and gently fold in one-third of the whites (this will help to prevent overmixing).
• Add the remaining whites and carefully fold until there are no visible streaks of white.
• Divide the batter between the two pans.
• Smooth the batter evenly with an offset spatula.
• Bake the cakes just until they have risen and feel like soft marshmallows, 8 to 10 minutes.
• Transfer the pans to wire racks and let the cakes cool to room temperature.
• Chill the cakes until cold, about 30 minutes.
• While the cakes are cooling, prepare the buttercream.
• For the peanut buttercream: In the bowl of a stand mixer fitted with the paddle attachment, cream the butter and peanut butter on medium speed until fluffy, about 2 minutes.
• Turn the speed to low, add the confectioners' sugar, salt and vanilla and mix for another 2 minutes.
• Add the cream, turn the speed to high, and beat for 1 minute.
• Cover and set aside.
• When cooled, remove the cakes from the refrigerator.
• Gently lift one cake from the pan, using the overhanging parchment as handles, and place it on a cutting board.
• Carefully separate the paper from the cake.
• Lay a piece of parchment on top of the cake and quickly flip the cake over.
• Remove the parchment and replace with a clean sheet of parchment.
• With a rolling pin, firmly roll over the cake to even it out and thin it out.
• Trim each cake to a 12-by-9-inch rectangle.
• Place in the freezer for 15 to 20 minutes; this firms it up, and if the cake is stuck to the parchment this allows you to flip one more time to release the paper.
• Repeat with the remaining cake.
• Spread a thin layer of jelly over the surface of both cakes.
• Divide the buttercream between the cakes and spread it evenly over the jelly, leaving a border at the top of one long side.
• (The rolls look best when the cake layer and buttercream layer are the same thickness.)
• Begin rolling up the cakes, one at a time, starting at a long side.
• The first roll is the most important-keep it tight.
• Continue rolling toward the top.
• It's best to go slowly and carefully.
• When you completed rolling a cake into a log, place it in the center of a new sheet of parchment.
• Take the paper above the roll and cover the roll with a little overlap.
• Now take a flat-edge utensil, like a bench scraper or a long spatula, and force it underneath the roll and push tight.
• This helps fill in any air pockets in the roll.
• Chill the rolls 15 to 20 minutes or overnight before cutting them; the colder, the better.
• For the chocolate shell: Put the chopped chocolate in a heatproof bowl and set it over a pan with 3 inches of simmering water.
• When the chocolate is completely melted, stir in the butter and oil.
• Set aside in a warm place.
• Remove the paper from the rolls.
• With a sharp knife, cut each roll into 6 even pieces; each will be about 2 inches wide.
• Place a screen over a sheet pan to allow excess chocolate to drip off.
• Working with one piece at a time, place a piece into the chocolate shell.
• Flip the piece over using a fork.
• Lift it out of the chocolate and tap off excess chocolate before setting it on the screen.
• Continue until each roll is completely coated.
• Move each roll slightly on the screen during drying so it doesn't stick.
• Once dry, carefully lift off the rolls and arrange them on a sheet pan.
• The rolls can be eaten right away or refrigerated, covered, for up to 4 days.
• Let them come to room temperature before serving.