Napoleon Cake with Cream

On a large board or work surface, pile the flour. Using a coarse grater and dusting it with flour to prevent sticking, grate the cold butter straight from the fridge into the flour.
Chop the flour and butter mixture with a large knife until you get fine crumbs.
Make a well in the center of the crumb mixture. Add a pinch of salt, half of the beaten egg, and half of the sour cream. Chop again with the knife until roughly combined.
Then add the remaining egg and sour cream, and chop again. Once the mixture forms coarse crumbs, press them together by hand into a dough ball. Divide the dough into 6–8 equal parts, form flat discs, wrap each one in plastic wrap, and refrigerate for at least 2 hours.
After 2 hours, roll out each disc one at a time directly on baking paper. Roll as thinly as possible (1–2 mm). Dust with flour as needed.
Cut the rolled dough into a circle using a cake pan or plate as a guide. (I usually use a 28–30 cm cake pan, but smaller sizes work fine if you’re making a single batch.) Save the trimmings – bake them too!
Transfer the dough (and trimmings) to a baking tray and bake at 200°C (390°F) until lightly golden.
The baked layers may shrink or become a bit misshapen – that’s okay! The more they puff up, the better, as it creates more layers.

While the dough is chilling, make the cream:

Heat the milk in a pot. In a bowl, mix together the sugar, flour, and starch. Add the lightly beaten eggs and vanilla sugar, and mix until smooth. Slowly pour this mixture into the boiling milk in a thin stream, stirring constantly.
Simmer the cream while stirring for about 5 minutes, then cool it to room temperature.
Beat the room-temperature butter with a mixer until fluffy. Then, one spoonful at a time, add the cooled custard cream, continuing to beat until smooth. Optional: Add a little lemon zest for a fresh twist.

Assembling the Cake:

Place the first cake layer smooth side down on a platter. Spread with cream, then add the next layer puffed side down, pressing slightly. Continue stacking in this way. (One layer can be spread with blackcurrant or cranberry jam for added tartness – it’s delicious!)
Once the cake is assembled, coat the top and sides with the remaining cream. Crush the baked trimmings and use them to coat the top and sides of the cake.
Refrigerate for at least overnight – the longer it sits, the better it tastes.
Just before serving, decorate with powdered sugar, cocoa powder, or any other decorations – keep in mind these may dissolve if done too early.

This cake is a labor of love, but the result is a flaky, creamy, nostalgic dessert that’s always worth the wait.