Beat the eggs with the sugar and add the remaining products in the order listed, after mixing the flour with baking powder ahead of time. Pour the mixture into a tray measuring 8″ (20 cm) x 13 3/4″ (35 cm), smeared with oil ahead of time and sprinkled with flour, even it out and put the tray in a preheated 356°F (180 °C) oven for about 25-30 min.
While the cake is baking, boil a syrup by mixing the sugar and water and once it comes to a boil, boil another 5 min.
Take the ready cake out and pour the syrup over it and leave to cool.
Boil the cream, while mixing the beaten eggs with the sugar and vanilla at the same time, in a bowl.
Add 2/5 cup (100 ml) from the cold milk and flour, stir until homogeneous.
Leave the rest of the milk to come to a boil on the stove and while stirring nonstop add the egg mixture, boil until the cream thickens. Toward the end, add the diced butter and stir until it dissolves fully.
Pour the cream over the cake and sprinkle 3-4 tbsp ground walnuts, leave in a cool area to harden for 2-3 hours, then serve cold.