Preheat oven: to 350°F (175°C) and line a jelly roll pan with parchment paper.
Beat eggs and sugar: until pale and fluffy, about 3–4 minutes.
Add lemon and vanilla: mixing in zest and juice for brightness.
Fold dry ingredients: flour, baking powder, and salt gently into batter.
Bake: 12–15 minutes until springy and light.
Roll warm sponge: using parchment to form shape, cool completely.
Spread jam: evenly over cooled cake, then re-roll tightly.
Dust and serve: with powdered sugar and fresh raspberries.
