Step 1

Preheat your oven to 425°F and line a half sheet baking pan with parchment paper. Cut a slit in the parchment paper in each of the four corners of the pan so that the parchment paper lies completely flat against the edges of the pan. Use office binder clips to clip the parchment paper to the edges of the pan. Set aside.

Step 2

Drop the egg whites into the bowl of a stand mixer. Whisk on high speed for about 2 to 3 minutes, until wet, soft peaks form. You want the whites to stay hanging on your whisk when they're held upside down, but you don't want them so stiff and dry like you would for a merengue (aim for softly curled tips). Temporarily set the whites aside.

Step 3

In a large bowl, whisk the egg yolks and sugar together until they're pale yellow. In a separate, smaller bowl, sift the cocoa powder, cake flour, coffee granules, baking powder, and salt together. Add these dry ingredients to the bowl containing the egg yolks and sugar. Whisk to combine - batter will be VERY thick and hard to mix, but this is normal, so just try your best to mix everything together.

Step 4

Add in half of the egg whites and use a rubber spatula to gently fold the whites into the batter. You don't have to be extra gentle at this point since you are merely trying to loosen up the batter with the egg whites. Now, add the remaining half of egg whites and, this time, be VERY gentle when folding the whites into the batter with your spatula; make light, long folds.

Step 5

Pour the batter into you're prepared pan and use your spatula to gently smooth out the batter. Don't tap the pan or move the pan side to side - you don't want to ruin the air bubbles you created with the whipped egg whites. Bake the cake for 6 to 7 minutes, or until the cake springs back when gently pressed by the tip of your finger (for me, it's always about 6 1/2 minutes in the oven). Let the cake slightly cool in the pan for 2 minutes - no longer.

Step 6

Meanwhile, prepare a light kitchen/tea towel by sprinkling powdered sugar all over it. Flip the cake out onto the towel and very gently peel the parchment paper off inch by inch. Grab one of the short sides of the cake and roll it towards the other short side, rolling the towel with it as you go. Let the cake remain in this rolled shape until it's completely cool. (Note: It’s important to do this while the cake is still warm as the cake is still flexible at this point and this prevents the cake from cracking or tearing as you roll it).

Step 7

Meanwhile, create the frosting by adding the chocolate chips, coffee granules, kahlua, unsalted butter, and vanilla extract to a medium bowl. Heat the heavy cream over medium-low heat until it’s hot but not boiling (the edges should begin to simmer and steam should rise from the cream). Pour this hot cream over the chocolate and contents in the bowl, then use a spoon to stir the mixture together until it’s completely smooth. Cover the bowl with a sheet of plastic wrap and refrigerate for 30 minutes - no longer.

Step 8

While the frosting chills, whip up your heavy cream in your stand mixer on high speed for one minute, or until the folds of the whisk start appearing in the cream. Add in the vanilla extract and the powdered sugar and continue to whisk on high until the cream is thick like frosting.

Step 9

Once your cake is cool, unroll your cake and use an offset spatula to spread the whipped cream all over the surface, leaving a very small border around the edges of the cake unfrosted. Gently roll the cake back up just like you did before (minus the towel), with the seam side facing down.

Step 10

Take a sharp knife and cut off a 2 inch slice from one end of the cake, cutting at an angle so that one end of the slice is 2 inches and the other end is closer to 1 inch. Take this slice and place the side of it that isn’t cut/exposed and attach it to the main cake log somewhere near the middle of the log.

Step 11

Use a hand mixer to whisk the chilled frosting for 15 to 25 seconds, or until you can see the whisk leaving indentations in the frosting. Don’t whisk any longer than that as it’ll ruin the frosting. Use a rubber spatula to smooth the frosting all over the cake log and it’s side stump. It’s preferred that you don’t use an offset spatula as the rubber spatula leaves nice streaks that make the cake look more like a log. Take a fork and run it down the length of the cake log several times. Adorn the cake with cranberries and rosemary for a more festive look.