For the sponge cake:
5 eggs
5 tablespoons sugar
5 tablespoons flour
For the cream:
150g butter
2 egg yolks
2 tablespoons flour
300ml milk
3/4 cup sugar
For the filling:
1 peach
2 tablespoons sugar
Making the sponge cake roll.
Preheat the oven to 180 degrees Celsius (350 degrees Fahrenheit).
Carefully separate the egg whites from the yolks.
Whip the egg whites until stiff, then gradually add half of the sugar and continue whipping the egg whites (using a mixer or blender).
In a separate bowl, combine the egg yolks with the remaining sugar and whip the egg yolk mixture well (again, using a mixer or blender).
Gently fold the whipped egg yolks into the egg whites, using a spoon to mix from the bottom up to avoid deflating the egg whites.
Sift the flour in small portions into the mixture, carefully folding until smooth.
Line a baking sheet with parchment paper. Pour the sponge cake batter onto the paper. Place the baking sheet on the middle rack of the oven. Bake at 180 degrees Celsius (about 350 degrees Fahrenheit) for approximately 15 minutes (baking time may vary depending on your oven). Do not open the oven!
Once the sponge cake is ready, remove it from the oven and quickly roll it up (I roll it up with the parchment paper). Leave the rolled cake seam-side down and cover it with a towel until it cools.
Making the cream.
In a bowl, whisk together the egg yolks, sugar, 2 tablespoons of flour, and half a cup of cold milk, using a mixer if desired.
Gently bring the remaining milk to a boil, then reduce the heat and slowly pour the egg mixture into the milk in a thin stream, stirring constantly to prevent the mixture from burning. Allow the mixture to cool.
Whip the butter with a mixer. Gradually add the cooled custard to the whipped butter (starting with 1-2 tablespoons at a time, then increasing to 3-4 tablespoons towards the end). Continue whipping until smooth. Add vanilla extract or vanilla sugar at the end, if desired.
Adjust the amount of butter in the cream to taste.
Making the filling.
Peel the peach, dice it, and mix it with sugar. Place this mixture over low heat, stirring until the sugar dissolves.
Once cooled, strain the peaches from the syrup.
Assembling the roll.
Carefully unroll the cooled sponge cake and remove the parchment paper.
Brush the sponge with the peach syrup.
Spread the cream over the sponge cake, add the peaches, and gently roll it up again.
