In large mixing bowl cream butter, sugar, eggs and vanilla with electric mixer. Combine dry ingredients and add to butter mixture. Mix until flour is moistened. Fold in apples and nuts. Spread in a greased 9x9 inch baking pan. Bake at 350 degrees F for 45 minutes or until done.
1/2 C. powdered sugar
1 Tbs. hot water
1/4 tsp. vanilla
Combine and drizzle over brownies.