For a 30 × 40 cm baking tray
4 eggs
3/4 cup sugar (190 g)
1 tsp vanilla
1 tsp lemon zest (optional)
1/2 cup flour (70 g)
2 tbsp starch
1 tbsp vegetable oil
powdered sugar for dusting
1 cup strawberry jam
1.5 cups heavy cream (35%) (360 ml)
2–4 tbsp powdered sugar
berries, powdered sugar for decoration (optional)
Separate the egg whites from the yolks
Beat the egg whites on high speed until fluffy, gradually adding sugar
Continue beating and add yolks, vanilla, and lemon zest
Reduce mixer speed to low, add flour and starch, then vegetable oil
Line a baking tray with parchment paper and lightly dust with powdered sugar
Spread the batter onto the tray
Bake in a preheated oven at 180°C for about 20 minutes
Turn the hot sponge onto parchment paper dusted with powdered sugar and cover with a towel until cooled
While the sponge cools, prepare the filling
If the jam is thick, warm it slightly in the microwave
Whip the cream with powdered sugar until thick
Remove parchment from the cooled sponge, spread jam evenly, then add whipped cream
Roll into a log
Decorate as desired
Store in the refrigerator