Mix sugar with 1/2 cup butter until fluffy. Add eggs and vanilla. Beat well.
Combine oatmeal, flour, baking powder and baking soda. Add to egg mixture, alternating with yogurt. Beat after each addition until just combined.
Fold in apples. Divide batter into two greased and floured round pans. Combine brown sugar, 1 tablespoon melted butter and nuts. Sprinkle on top.
Bake at 350°F for 30-35 minutes.
Submitted by: SharonV