1. Make Raspberry Swirl: Cook raspberries, sugar, and lemon juice until berries break down. Add cornstarch slurry and cook until thickened. Cool completely.
2. Make Sponge: Preheat oven to 350°F (175°C). Line pan with parchment. Beat eggs and sugar 4–5 minutes until pale and airy. Stir in vanilla. Whisk flour, baking powder, and salt separately, then gently fold into egg mixture.
3. Bake: Spread batter into pan. Bake 10–12 minutes or until cake springs back when touched.
4. Roll Warm Cake: Dust a towel with powdered sugar. Turn cake onto towel, peel parchment, and roll up tightly. Cool completely.
5. Make Filling: Whip cream, powdered sugar, and vanilla to soft peaks.
6. Assemble: Unroll cooled cake, spread cream evenly, swirl raspberry mixture over, and roll tightly.
7. Chill & Serve: Refrigerate 1–2 hours. Dust with powdered sugar before slicing.

Tips:

• Roll cake while warm to prevent cracking.
• Dust generously to prevent sticking.
• Chill filling slightly for cleaner swirls.
• Use a serrated knife for smooth slices.

Variations:

• Add lemon zest to sponge.
• Use strawberry swirl.
• Spread raspberry jam for extra color.
• Add white chocolate shavings.
• Garnish with fresh mint.

Storage:

• Refrigerate: Up to 3 days.
• Freeze: Up to 1 month (wrap tightly).
• Make-Ahead: Bake sponge one day early.

FAQs:

• Frozen raspberries? Yes—thaw lightly.
• Cracking? Roll cake while warm.
• Dairy-free? Use whipped coconut cream.
• Sticky roll? Dust towel with more powdered sugar.
• Freeze? Yes—wrap tightly to avoid freezer burn.