Cut in butter with a pastry blender until mixture resembles coarse meal.
Stir in cheese and raisins. Make a well in the center of mixture.
Combine egg and milk. Add to dry ingredients, stirring just until moistened. (If dough is too dry add more milk, 1 tablespoon at a time until you get a moistened batter.)
Spoon batter into greased and floured muffin pans.