Napoleon Cake with Flaky Layers

Whisk together the flour and salt in a bowl. Coarsely grate the frozen butter directly into the flour and quickly rub it with your fingers into a crumbly texture.

Pour in the mixture of egg, vinegar, and ice water. Bring the dough together without over-kneading, leaving small pieces of butter intact to ensure flakiness.

Divide the dough into 12 balls, wrap them in plastic wrap, and chill for 2–3 hours, or preferably overnight.

Roll each ball out thinly (2–3 mm) and trim into a 26 cm circle. Bake at 180°C for 4–5 minutes until golden spots appear, being careful not to overbake.

Bake an extra layer using the dough scraps to use for crumbs later.

For the cream, beat the butter until pale and fluffy, then gradually add the condensed milk spoonful by spoonful while continuing to whip. Mix in the vanilla.

Layer the baked sheets with the cream, pressing them gently together. Coat the sides and top generously with the crushed pastry scraps.