How to make:
1. Preheat oven to 170*C. Whisk together oil, eggs, sugars, pumpkin, spices and baking powder.
2. Fold in the flours until just mixed. Set aside.
3. Mix the walnuts, cinnamon and maple syrup together in a small bowl until the walnuts are coated evenly.
4. Line and grease a 21 or 22cm cake tin. Fill this with half of the cake mixture. Sprinkle over half of the walnut mix. Add the remaining batter and top with the remaining walnut mix.
5. Bake for 40-50 minutes until the cake springs back when lightly touched, or a skewer comes out clean. Leave in the tin for at least 10 minutes before turning onto a cooling rack.