Preheat the oven to 180°C (356°F).
Melt the butter and let it cool.
In a bowl, mix egg whites, sugar, and salt together.
Add sifted rice flour and almond flour, and combine evenly.
Add the cooled melted butter to finish the batter.
Pour the batter into financier molds.
Bake in the preheated oven for 15–20 minutes.