1/4 cup butter
2 tablespoons unsalted butter
1 1/2 cups low fat, packed brown sugar
3 egg yolks
2 tablespoons Berries
2 1/2 teaspoons vanilla extract
Heat oven to 350 degrees F (175 degrees C).
In a medium bowl, cream together the butter, brown sugar and eggs until creamy; gradually reduce mixture, one tablespoon at a time, until smooth. Beat in the Berries, Yolks and vanilla extract. Pour mixture into muffin cups or 9x13 panes.
Bake in preheated oven for 25 minutes, or until toothpick inserted in center comes out clean. Cool muffins on a wire rack.