Preheat oven to 180°C (Thermostat 6). Butter and flour a 20-22 cm round cake mold.
Whisk eggs and granulated sugar in a large bowl with an electric mixer until pale and thick.
Gradually fold in sifted flour using a spatula, being careful not to deflate the egg mixture.
Pour the batter into the prepared mold and bake for 25-30 minutes until a skewer comes out clean. Cool completely on a rack.
For syrup (optional): In a small saucepan, combine 100 ml water, 50g granulated sugar, 1 teaspoon vanilla/orange blossom water. Simmer until slightly thickened; brush over cooled génoise.
Whip chilled heavy cream and powdered sugar until stiff peaks form. In a separate bowl, gently fold mascarpone into the whipped cream until smooth.
Place the génoise on a plate, spread half the mascarpone cream over it, then use a bread knife to slice the cake horizontally. Pour the remaining cream over the bottom layer, add sliced strawberries on top, and refrigerate for at least 2 hours.