Mix room temperature unsalted butter and powdered sugar together.

Add the room temperature egg yolk and mix well.

Sift cake flour, almond flour, salt, and ground Earl Grey tea leaves into the mixture.

Cut through the dough with a spatula until no dry flour is visible.

Gather the dough into a single mass.

Knead the dough lightly several times, but do not overwork it.

Roll the dough into a log approximately 3cm in diameter.

Wrap the dough log in parchment paper or foil and freeze for 1 hour.

Brush the dough log with egg white and coat with sugar.

Slice the dough into 1cm thick rounds.

Place the slices on a baking sheet lined with parchment paper.

Bake at 180°C for 15-18 minutes. Adjust time and temperature based on your oven.

Let the cookies cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.