In separate bowl, sift together dry ingredients. Add to wet ingredients and mix.
Stir in walnuts
Pour into pan and bake approximately 35 minutes or until toothpick comes out clean
Allow to cool
Frosting
Mix together butter, cream cheese, and maple syrup. Add powdered sugar 1/2 at a time. Finally, fold in walnuts. Spread on cooled cake. Sprinkle with additional walnuts if desired.