In a large bowl sift together the flour, 3 tablespoons of cocoa powder, and baking powder.

Next, add in the sugar, vanilla, eggs, and oil and vigorously whisk together until smooth and combined.

Transfer the mixture to a 13x18 cookie sheet tray that has been lined with parchment paper and spread the batter out evenly using an offset spatula.

Bake at 350° for 15-17 minutes and then invert the cake onto a large clean kitchen towel that’s been dusted with ¼ cup of cocoa powder. Be sure to remove the parchment paper.

Roll the cake up in the towel and let it completely cool to room temperature, which takes about 2 to 2 ½ hours.

In the meantime, make the filling by whisking together the whipped cream, sugar, vanilla, and cocoa powder until medium-stiff peaks have formed.

Next, add in the mascarpone cheese and whisk until stiff peaks have formed. Set in the refrigerator to keep cool until ready to use it.

Now, prepare the ganache, and optional sugared cranberries and rosemary, as well as meringue mushrooms.

Once the cake is completely cooled, gently unroll it, and then evenly spread the mascarpone whipped cream all over the enter from edge to edge.

Roll the cake up tightly and make sure the filling is not coming out of the edges.

Roll the cake up tightly in plastic wrap and chill it for about 30 minutes in the refrigerator to help restabilize the shape and filling.

Slice the cake towards the top at an angle and then attach it to the side of the cake using some ganache or leftover whipped cream filling.

Spread the ganache all over the top and sides of the yule log leaving the cut ends opened.

Take a fork and run streaks down the sides and top of the cake.