1. Prepare the Pan and Oven:

• Preheat oven to 375°F (190°C).
• Grease the jelly roll pan. Line it with parchment paper, ensuring the parchment goes up the sides slightly (leave an overhang on the short sides if possible). Grease the parchment paper as well.

2. Make the Sponge Cake Batter:

• In a large bowl, beat the eggs with the granulated sugar and vanilla extract using an electric mixer on high speed for about 5-7 minutes, until the mixture is very thick, pale, and ribbony (when you lift the beaters, the batter falls back in a ribbon that stays on the surface for a few seconds).
• In a small bowl, whisk together the milk and melted butter (or oil).
• Sift the flour, cocoa powder, baking powder, and salt together into a separate bowl.
• With the mixer on low speed, gradually pour the milk/butter mixture into the egg mixture, mixing just until combined. Do not overmix.
• Add the sifted dry ingredients to the wet ingredients in two or three additions, folding gently with a spatula after each addition until just combined. Be careful not to deflate the batter.
• Pour the batter into the prepared pan and spread it evenly with an offset spatula, ensuring it reaches the corners.

3. Bake the Sponge:

• Bake for 10-15 minutes, or until the cake springs back when lightly touched in the center and the edges start to pull away slightly from the sides of the pan. Watch carefully to avoid overbaking.

4. Roll the Cake:

• While the cake is baking, lay a clean kitchen towel flat on your work surface and dust it generously and evenly with powdered sugar or cocoa powder.
• As soon as the cake comes out of the oven, immediately invert it onto the prepared towel.
• Carefully peel off the parchment paper. If it sticks, gently loosen it with a knife.
• While the cake is still hot, starting from one of the short ends, gently but firmly roll the cake up with the towel inside.
• Place the rolled cake (seam-side down) on a wire rack and let it cool completely in the towel (about 1 hour).

5. Prepare the Raspberry Filling:

• Gently rinse and pat dry the fresh raspberries. Set aside a few for garnish if desired.
• In a large, chilled bowl, whip the cold heavy cream with the powdered sugar and vanilla extract using an electric mixer on medium-high speed until stiff peaks form.
• Optional: Gently fold in the raspberry jam/preserves if using.

6. Assemble the Swiss Roll:

• Carefully unroll the cooled cake, removing the towel.
• Spread the whipped cream evenly over the inside surface of the cake, leaving about a ½ to 1-inch border along the far short edge.
• Dot the fresh raspberries evenly over the cream. You can gently press them in slightly.
• Carefully re-roll the cake (without the towel this time), starting from the same short end you started rolling from initially. Try to roll it snugly but gently to avoid squeezing out too much filling.
• Place the roll seam-side down on a serving platter or a piece of parchment/foil.

7. Chill:

• Chill the cake roll in the refrigerator for at least 1-2 hours (longer is better) to allow the filling to set firmly, making it easier to slice neatly.

8. Garnish and Serve:

• Before serving, trim the ends of the roll for a cleaner look (optional).
• Garnish as desired: Dust generously with powdered sugar, drizzle with chocolate ganache, pipe on any extra whipped cream, and/or top with fresh raspberries and chocolate shavings.
• Slice the chilled roll using a sharp, thin knife (dipping the knife in hot water and wiping it clean between cuts helps create neat slices).