1Preheat oven to 350 degrees F (175 degrees C). Grease and flour two 9 inch round cake pans. Sift flour, salt and baking powder together and set aside.
2In a large bowl, cream butter, shortening and sugar until light and fluffy. Add eggs one at a time and beat in well. Add flour mixture alternately with milk and mix well. Add vanilla and walnut extract. Fold in nuts.
3Pour batter into 2 - 9 inch pans. Bake at 350 degrees F (175 degrees C) for 35 to 40 minutes, or until a toothpick inserted into the cake comes out clean.