Creating a Chocolate Yule Log may seem daunting, but following these step-by-step instructions will simplify the process and yield a stunning dessert.

Step 1: Preheat & Prepare

1. Preheat your oven to 400°F (200°C).
2. Spray a 13×18 inch baking sheet with cooking spray and line it with parchment paper. Spray the parchment paper as well to prevent sticking.

Step 2: Make the Cake Batter

1. In a stand mixer, beat the eggs and sugar at medium speed for 2-3 minutes until the mixture is fluffy.
2. Lower the speed and add the vanilla extract, cocoa powder, flour, and salt. Mix briefly until just combined.

Step 3: Bake the Cake

1. Pour the batter onto the prepared baking sheet and spread it evenly using a spatula.
2. Bake for 8-10 minutes, or until the cake is set and dry on top.

Step 4: Make the Buttercream

1. In a clean bowl, beat the softened butter and powdered sugar on low speed until combined.
2. Increase the speed to medium and continue beating for 2 minutes until the mixture is fluffy.
3. Add the pinch of salt, milk, and mascarpone cheese, mixing for another 30 seconds until smooth.

Step 5: Roll the Cake

1. Once baked, dust the top of the cake with powdered sugar.
2. Run a knife around the edges to loosen it from the baking sheet.
3. Place a clean kitchen towel over the cake, then carefully flip it onto a second baking sheet.
4. Peel off the parchment paper and dust again with powdered sugar.
5. Carefully roll the cake in the towel and let it sit for 10 minutes before gently unrolling it.

Step 6: Add Filling & Roll Again

1. Spread ¾ of the prepared buttercream evenly over the unrolled cake.
2. Roll the cake back up gently, this time without the towel.
3. Wrap the rolled cake in plastic wrap and refrigerate for at least 2 hours to set.

Step 7: Make the Ganache

1. Combine the heavy cream and dark chocolate chips in a microwave-safe bowl.
2. Heat for 1 minute, then let sit for 2 minutes before stirring until smooth and glossy.

Step 8: Assemble the Yule Log

1. Cut a 3-inch piece off one end of the rolled cake to create a branch.
2. Frost the side of the main log and the cut piece with ganache.
3. Attach the cut piece to the side of the main log to mimic a branch, using ganache as glue.
4. Dust the finished log with additional powdered sugar for a snowy effect.