Preheat your oven to 160°C (325°F) and grease your financier pans.

In a small saucepan, melt unsalted butter over low to medium heat until golden brown.

In a mixing bowl, sift together plain flour, almond meal, icing sugar, and a pinch of salt.

Lightly whisk the egg whites in a separate bowl until frothy, then combine with the dry mixture.

Gently fold the cooled brown butter into the mixture and add vanilla extract if desired.

Fill each compartment of the prepared financier pans with the batter and sprinkle on flaked almonds if using.

Bake in the preheated oven for about 12–14 minutes until lightly golden and set.

Remove from the oven, let cool for about 15 minutes, then gently remove from the pans.