For the sponge cake: 1) Beat the egg yolks with the granulated sugar until the mixture becomes pale. 2) Sift the flour and cornstarch, then mix them with the sugar and egg yolk mixture. 3) Whip the egg whites with a pinch of salt until stiff peaks form. 4) Gently fold the egg whites into the batter in batches using a spatula until the batter is smooth and forms ribbons. 5) Spread the batter evenly on a jelly roll pan. 6) Bake in a preheated oven at 350°F (180°C) for 10 to 15 minutes.

For the cream: Mix all the ingredients together and whip until the cream doubles in volume.

To assemble the Yule log: 1) Brush the sponge cake with raspberry sauce. 2) Spread a quarter of the cream over the cake and sprinkle with raspberries. 3) Roll up the cake tightly to form a log. 4) Spread the remaining cream over the log and decorate as desired.