Preheat oven to 375 degrees. Line a 10x15 jelly roll sheet pan with parchment paper. Set aside.
Add sugar, applesauce, and eggs to a mixing bowl and mix for 3 minutes.
Add the remaining ingredients and mix until just combined. Don't over mix.
Pour batter onto prepared sheet pan. Use an offset spatula to smooth it out.
Bake for 13-15 minutes, or until a toothpick comes out clean.
Remove from the oven. Using the parchment paper roll up the cake and place on a cooling rack. Allow to come to room temperature and follow with the remaining steps.
Chocolate Cream Cheese Filling
Add all of the ingredients to a mixer and mix until smooth and creamy.
Slowly roll out the cake. Spread the filling evenly onto the cake.
Gently roll back up.
If you would like a side log piece, cut a 3" piece off one end and position where you like.
Toasted Marshmallow Frosting
Create a double boiler. Bring a pot of water to a simmer and fit a glass bowl over the top. Make sure the water never touches the bottom of the bowl. You want the steam to cook the eggs gently.
Add the egg whites, cream of tartar, and sugar to the glass bowl. Whisk continuously for approximately 5 minutes until the mixture becomes light and frothy.
Transfer the egg white mixture to a mixing bowl. Add the toasted marshmallow flavoring and mix on high for 5 minutes or until it increases in volume, becomes thick, and holds its shape. This is called stiff peaks.
Spread the toasted marshmallow frosting over the yule log. To create a textured look, use a knife to create your desired pattern. Toast with a kitchen torch.
Add crushed graham crackers around the yule log for serving.