Preheat the oven to 200 degrees and flush a silicone mold with water. Do not have a silicone mold, use a normal baking grease but that well with butter or use baking paper.
Soften the butter, for example, in the microwave. Add the salt and sugar and stir well. Stir well the flour little by little this is through the mixture and mix until smooth. Spoon into the mold and smooth it with the back of a wet spoon. Bake 18-20 minutes in the oven. When he‘s ready to cool off for a minute and then remove the mold.