Use a 23×13cm loaf tin. Coat with cooking spray. Preheat oven to 180°C. Place flour in a large bowl and make a well in centre.
Place butter in a medium bowl; beat until creamy; mix in the syrup. Beat in the egg, then add the milk and vanilla. Pour mixture into the well; stir just until combined. Do not overbeat; a few lumps of flour should still be visible. Stir in the walnuts.
Scrape the batter into the loaf tin. Bake for about 50 minutes until golden brown and a skewer inserted in the centre comes out with moist crumbs attached to it. If the bread is browning too quickly, cover it loosely with foil during the last 15 minutes of baking.
Place pan on wire rack; leave bread to cool for 10 minutes. Turn bread out onto wire rack to cool completely.
Pure maple syrup, the top of the line, comes from the sap of maple trees, gathered through a process known as maple tapping. Maple-flavoured syrup is a mixture of a less expensive syrup, such as corn syrup, and contains only a small percentage of pure maple syrup. Pancake syrup is often corn syrup flavoured with artificial maple extract. For this bread recipe, buy the best syrup that you can afford. The better the syrup, the better the flavour will be.