4 squars of parchment paper (approximately 14-inches (about 36 cm) per side)
Ingredients
Inside Layer
10.5ouncesground walnutssubstitute with hazelnuts or almonds
10.5ouncesbaking chocolatefinely grated
10.5ouncesconfectioner's sugar
6tablespoonsmilk
.5-1teaspoonrum or vanilla extractadjust to taste, or avoid, substitute with sweet liqueurs
Inside Layer
4egg yolks
7ouncesconfectioner's sugar, plus a little more
1-2tablespoonsbutter
Instructions
Outside Layer
In a large bowl, combine walnuts, chocolate, and confectioner's sugar. Whisk until integrated. Add vanilla extract and milk. Take over with your hands, and knead vigorously for 3-4 minutes, or until you get a congealed, semi-hard, thick mixture resembling wet sand in texture.
Divide into four equal parts. Work each into a smaller rectangle, the thickness of 2-3 fingers. Set aside.
Outside Layer
Make a water boiler by filling a smaller pot ⅔ with water and bringing it to a rolling boil. Reduce temperature to low, or medium. Place a stainless steel bowl (or a smaller pot) into the large one making sure it's halfway in.
Add yolks and sugar to the smaller pot, and mix with a hand mixer until egg yolks become light yellow, or about 5 minutes. Hold the pot with the other hand the best you can, making sure: 1. you're mixing everything, and 2. you're being careful not to flip the pots over and burn yourself. (This part is crucial as you're processing the egg yolks.)
Add butter to the pot, and continue mixing. Once the mixture is completely smooth (3-4 minutes), remove off heat.
Combine
Take one sheet of parchment paper onto your working area, and sprinkle it with confectioner's sugar. Then take one chocolate layer and spread it out into a rectangle with a rolling pin until it's the thickness of a finger (approximately). Take ¼ of the yellow layer and spread over the top evenly. Roll the cake in starting with the longer end.
Cover in baking paper and leave in the fridge or freezer depending on when you plan to consume it. (Let it stiffen for at least 3-4 hours before serving, preferably overnight.) Repeat the steps for the remaining 3 rolls.
Handling
Serve: Take out of the fridge then cut into 1-inch pieces just before serving. Enjoy chocolate cake rolls with a beverage of choice.Store: Keep chocolate cake rolls in an airtight container in the fridge for 3-4 days.Freeze: Chocolate cake rolls are great for freezing. Keep them in an airtight bag or container for up to 2 weeks in the freezer. Transfer to the fridge a couple of hours before you plan to consume them.
Video
Notes
Nutritional Information
Nutritional information was calculated for ¼ of one chocolate roll, or a few pieces.