1. Preheat your oven to 482°F or 250°C.

2. Whisk together the eggs and sugar in a large mixing bowl until smooth.

3. In a separate bowl combine the flour and baking powder then add this mixture to the egg mixture, whisking until well combined.

4. Add the water and mix until a smooth batter forms.

5. Line a 30x40 cm or 12x16 inch baking pan with parchment paper and pour the batter into it, smoothing the top.

6. Bake in the preheated oven for about 5 minutes until the edges are lightly golden.

7. Remove the cake from the oven and carefully invert it onto a clean dry towel, gently peeling off the parchment paper from the bottom of the cake. Allow it to cool under the towel.

8. Soften the butter at room temperature, then spread it evenly over the cooled cake, followed by a layer of strawberry jam.

9. Roll the cake into a tight log starting from the long side, using parchment paper to help you roll the cake evenly.