Place the butter in a small saucepan over medium heat. Bring the butter to a low boil, stirring from time to time. Remove the saucepan from the heat once the butter has turned golden brown and smells nutty. Set aside.
Place the almond and 1/2 cup of sugar in a food processor and process until the mixture has turned into sweetened almond flour. Place the almond mixture into another small saucepan and add the remaining 1/2 cup of sugar. Add the egg whites, stir, and place the saucepan over low heat. Heat the mixture, stirring constantly with a wooden spoon, until the mixture has heated through, is slightly white and runny. Remove from heat.
Add the flour and stir to mix. Gradually stir in the browned butter. Transfer the mixture to a heatproof bowl and let cool, until it has reached room temperature. Press a piece of plastic wrap on the surface and place in the refrigerator for at least one hour.
Preheat the oven to 400 degrees. Butter molds and then dust generously with flour. Fill each mold almost to the top with batter.
Bake for 15 minutes, or until the cakes are golden
Remove from oven and un-mold as soon as possible. If the cakes are sticking, you can run a blunt knife around the edges to help remove the cakes. Transfer to a cooling rack.