Step 1

Preheat oven to 350 F. Lightly grease a rimmed cookie sheet or jelly roll pan. Line with parchment paper, grease the top of the paper, and dust with 1 Tbsp cocoa powder. Set aside.

Step 2

In a large bowl, beat egg yolks, sweetener, 2Tbsp cocoa powder, salt, coffee, and vanilla extract together until the mixture is thick and light brown. In a separate bowl with clean beaters, beat egg whites until stiff peaks form. Gently fold egg whites into chocolate mixture, one-third of the batch at a time, until smooth. Pour into the prepared baking sheet and bake at 350 for 20 minutes.

Step 3

While the cake is baking, layout kitchen towel and sprinkles it with 1/4 cup cocoa powder. After the cake is finished baking and has cooled slightly, invert onto the cocoa-covered towel and peel off the top piece of parchment paper. Roll up carefully inside a towel and let it cool while you make the filling.

Step 4

To make the filling, beat whipping cream, sweetener, cocoa powder, and instant espresso powder together until stiff. Unroll cooled cake from the towel, spread on the filling, and roll cake back up. Trim the ends with a serrated knife.

Step 5

Optional: sprinkle powdered sugar substitute (Swerve) on top for "snow."