For the pastry cream, mix the eggs with the water, and combine sugar with cornstarch until there are no lumps.
Slowly heat the mixture in a pot until it starts to thicken, then let it boil for a few seconds. Turn off the heat and set aside to rest.
For the syrup, combine water and sugar in a pot and bring to a boil. Set aside.
Now, for the sponge, using a mixer, whisk the eggs, sugar, and honey for 7 minutes.
Then add the flour in two or three parts while gently mixing with a spatula.
Gradually add the flour in two or three parts, gently folding with a spatula.
Grease baking paper with butter and spread the mixture on it. Preheat the oven to 200°C (392°F) and bake for 10 minutes.
Remove and let cool.
Once cool, soak in syrup, and then spread with pastry cream.
Carefully roll up the sponge and cut into servings.