How to cook
Whip the eggs with the sugar to a fluffy cream. Add the flour, mixed with the baking powder and vanilla, stir with a spatula until it becomes a homogeneous mixture. Pour the mixture into a 11 3/4″ (30 cm) diameter oven dish laid out with baking paper.
Bake in a preheated 356°F (180 °C) oven until ready. Cut the layer into 2 along the horizontal line.
For the syrup, caramelize the sugar in a metal container to the desired color, pour the water in it and boil until it dissolves, then syrup both parts of the layer with it.
For the milk cream, set aside 4/5 cup (200 ml) of the cold milk, dissolve the flour in it to get a smooth mixture and add the vanilla. Put the rest of the milk in a pot along with the sugar, put it on low heat and stir periodically.
Shortly before it comes to a boil, pour in the dissolved flour in a thin trickle while stirring nonstop. Add the cut into pieces butter and stir until it melts. Boil the cream to the desired consistency.
Assemble the cake with the hot cream by alternating between layer and cream. Smear the cake with cream on its sides as well. Sprinkle the cake generously with walnuts on all sides, leave it to cool completely and serve.