Combine oats and butter/sour milk in small bowl. Mix well and let stand 1 hour.
Sift together flour, baking powder, baking soda and salt; set aside. Cream together butter and brown sugar in mixing bowl, using electric mixer at medium speed. Add egg; beat until light and fluffy.
Add dry ingredients alterantely with oat mixture to creamed mixture, blending well after each addition. Spoon batter into greased 2 1/2-inch muffin-pan cups, filling 2/3rds full.
Bake in 400 degree F. oven 20 minutes or until golden brown. Serve hot with homemade jam or preserves.