For filling: In a saucepan, melt butter. Stir in flour until creamy and smooth. Add brown sugar, cinnamon and nutmeg. Mixture will be sugary and grainy (don't get this mixture too hot or it will get hard). Stirring frequently, add apples and cook over low/medium heat until apples are tender, approximately 10 minutes. Remove from heat and stir in nuts. Cool apple mixture.

For batter: In a mixing bowl, cream soft butter and sugar. Add eggs one at a time, beating well after each addition. Beat in vanilla. Combine dry ingredients; stirring in by hand alternate flour and sour cream. Spoon batter into regular size greased muffin tins- not quite half full. With teaspoon, spoon apple mixture into center (do not spread). Top with remaining batter. Sprinkle with cinnamon-sugar and dust with finely chopped nuts. Bake at 350 degrees for 20 minutes. Cool 5 minutes before removing from pans to wire racks.

Yields 24 muffins.