Queijadas

Preheat oven to 325 degrees F (165 degrees C).
In a blender, combine eggs, sugar and butter. Blend until smooth. Pour in flour and milk, a little at a time, blending until smooth again. Stir in vanilla.
Pour into muffin tins, filling 3/4 full. Bake in preheated oven 45 minutes, until golden brown. Serve hot or cold.