1. Preheat the oven to 350°F. Line a 10×15-inch jelly roll pan with parchment paper and lightly grease it.

2. Beat the eggs and granulated sugar for 4 to 5 minutes until pale, thick, and fluffy. Mix in the vanilla extract.

3. Sift together the flour, cocoa powder, baking powder, and salt. Gently fold the dry ingredients into the egg mixture until no streaks remain.

4. Spread the batter evenly in the prepared pan and bake for 10 to 12 minutes, just until the cake springs back lightly when touched.

5. Turn the warm cake onto a clean kitchen towel dusted lightly with cocoa powder or powdered sugar. Remove the parchment and roll the cake up gently with the towel from the short end. Let it cool completely.

6. Beat the cream cheese and powdered sugar until smooth. Mix in the melted white chocolate and lemon zest.

7. In a separate bowl, whip the heavy cream to soft peaks, then fold it into the white chocolate mixture. Gently fold in the chopped raspberries.

8. Carefully unroll the cooled cake and spread the filling evenly over the surface, leaving a small border around the edges. Roll the cake back up gently and place seam-side down. Chill for at least 1 hour.

9. Melt the remaining 4 ounces white chocolate with the butter until smooth. Spread or drizzle it over the chilled yule log and create light textured lines with a fork or spatula.

10. Garnish with extra raspberries and a dusting of powdered sugar before slicing and serving.