Cream butter and brown sugar together in a large bowl until light and fluffy. Beat in egg. Add milk. Mix.

Combine remaining 5 ingredients in medium bowl. Make a well in centre. Add butter mixture to well. Stir until just moistened. Fill greased muffin cups 3/4 full. Bake in 400° f (205°c) oven for about 18 minutes until wooden pick inserted in centre of muffin comes out clean. Let stand in pan for 5 minutes before turning out onto wire rack to cool. Makes 12 muffins