Beat the butter with sugar and vanilla until fluffy. Add the eggs and beat again.
Separately mix flour, salt and baking powder. Start gradually adding the resulting mass to the butter-egg mixture. Mix the dough until smooth. It should have the consistency of thick sour cream. Then add raisins and mix again.
Prepare the forms. Fill them with dough up to half. Bake for 20-25 minutes. Remove the muffins from the oven and let them cool slightly before serving.