Filled with a creamy French silk filling, this French Silk Cake Roll has all the flavor of a French Silk Pie rolled up in a chocolate cake!
Preheat the oven to 350°F.
Line a 15x10-inch jelly roll pan with parchment paper. Leave extra parchment paper hanging over the 15-inch sides for easy removal of the cake. You can also spray the parchment paper with a non-stick spray, but it is not necessary.
In a medium bowl, whisk together flour, cocoa powder, baking powder, and salt until combined. Set aside.
In a separate bowl, whisk together eggs and granulated sugar for about 1 minute, or until thick. Add in the oil, vanilla extract, and coffee (use hot water if you don't have coffee) until combined.
Fold in the flour mixture and stir until combined.
Pour the batter into your prepared jelly roll pan. Smooth out the batter and gently tap on the counter.
Bake in a 350°F oven for 10-12 minutes, or until the center no longer appears wet and an inserted toothpick is removed with a few crumbs.
One a clean hard surface such as a countertop, lay out a clean dish towel and generously sprinkle with confectioners sugar or cocoa powder.
Once the cake is done baking, carefully (using oven mitts) flip it over onto the clean dish towel in one quick motion. Fold about 2 inches of the towel over the edge and start rolling the cake up into a tight roll. Allow to cool for 2-3 hours, or until completely room temperature.
(Start this step about 30 minutes before you are ready to assemble the cake.)
Chop dark chocolate and microwave in 30-second increments until melted. (about 1 1/2 minutes total) Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, add the butter and sugar. Turn mixer on high for 1 minute. Butter and sugar should be light and fluffy.
With the mixer on low or with the mixer off, pour in the melted (and slightly cooled) chocolate. Allow ingredients to combine for 30 seconds then turn the mixer off and scrape down the sides.
Add in eggs and turn the mixer on high for 10 minutes. The filling should lighten, increase in volume, and appear very smooth and shiny. (The filling will darken after assembly.)
In a large bowl or in the bowl of a stand mixer fitted with the whisk attachment, pour the heavy whipping cream. (Can also use hand-held mixer) Whip for about 2 minutes, or until soft peaks occur.
After the rolled cake has cooled (2-3 hours), gently unroll the cake, taking care not to tear or crack the cake. It will relax more as it sits unrolled. (If you do not want to get the towel dirty, remove the towel and place the cake on a clean sheet pan.)
Spread French silk filling on top, leaving about a 1/4 inch space on all four sides. It should be a thin, even layer.
Gently roll the cake back into its rolled shape. Wrap with plastic wrap and refrigerate for at least 2 hours.
After refrigerating, top with your homemade whipped topping (or cool whip), carefully spreading it on all exposed areas.
Top with chocolate shavings.
Can be served immediately or chilled until ready to serve. (I always cut off the ends before serving, just to make it prettier.)