Heat unsalted butter in a saucepan until it turns brown.

In a bowl, whisk egg whites and powdered sugar together.

Sift the dry ingredients and mix them into the egg white mixture.

Gradually add the browned butter while whisking continuously.

Mix in yuzu marmalade and lemon juice.

Wrap the batter and refrigerate for at least 1 hour.

Pipe the chilled batter into molds using a piping bag.

Bake in a preheated oven at 180°C for 10–12 minutes, then cool on a wire rack.