Preheat oven to 425 degrees. Grease 12 muffin cups. In each cup put 2 teaspoons maple syrup, 1 teaspoon chopped walnuts and 1/2 teaspoon melted butter. Sift together dry ingredients and set aside. Beat together syrup, egg, milk and oil. Add to dry ingredients, stirring just enough to blend. Fill each cup 2/3 full. Bake for 20 minutes. Invert muffin tins onto a wire rack covered with wax paper, and let stand for a few minutes. Best when served warm.