DOUGH: Combine butter, sugar and salt in a bowl. Scald milk (heat until right before it boils) and pour into bowl. Stir until butter has melts and every is mixed. Let cool to lukewarm temperature. Meanwhile, dissolve 2 tsp yeast in 60 ml (1/4 cup) warm water).

Add 120 g (1 cup) flour and the yeast mixture to the bowl. Mix well and let sit in a warm place until it becomes bubbly.

Whisk in 1 egg and 2 yolks. Gradually beat in 120-180 g (1/2 to 3/4 cup) flour until it's soft, light and smooth. You may need more or less flour depending on how wet the dough is.

Knead the dough on floured surface until smooth and elastic. Shape into a ball and put back into bowl. Cover and let rise until doubled, about 1-2 hours.

After the dough has risen, lightly knead to push out the air. Place it on a baking sheet (greased or w/ parchment paper), and roll out into a circle or square about 4 cm (3/4 inch) thick. Cover and let rise again until doubled, about 30 min.

TOPPING: Meanwhile, heat the 60 ml (1/4 cup) milk 40 g (2 1/2 Tbsp) butter and stir in 60 g (5 Tbsp) sugar and the slivered almonds. Simmer on low heat until mixture is smooth and milk has soaked in.

Let it cool a bit and spread on dough once it has finished rising.

BAKE: Preheat oven to 350°F/180°C for 25-30 min or until golden brown and glossy. Let cool on a rack. My dough got a little to big so I sliced off the extra edges... :/

FILLING: While the cake is baking, make the filling. Beat 3 egg yolks with 45 g (4 Tbsp) sugar until thick and pale yellow. Lightly mix in about 1 1/2 Tbsp flour. Scald 150 ml (2/3 cup) milk. If using the vanilla bean, add it to the milk while scalding. (If using extract, you'll add later.)

Very slowly pour the scalded milk into egg yolk mixture, stirring as you do.

Pour the mixture into a saucepan and cook over low heat, stirring constantly. Remove from heat as soon as it reaches boiling point (but don't boil!!).

If using the vanilla extract, add it now, or remove the bean. Let cool completely (you can brush w/ a little melted butter to help prevent skin from forming). Stir the custard before spreading on cake.

When cake has cooled, cut in half to form two layers. Spread the bottom half with the vanilla custard filling and sandwich with the almond-y top half.