First lets preheat the oven to 400F. Using butter grease 9 by 2 inches round cake pan. Place a cut out parchment paper and place it on the bottom of the pan.
In a big bowl combine carrots, walnuts, raisins and 1 tbsp of flour and give it a mix using big spoon. Then stir it into the batter, mix until combined.
Place the batter into the baking pan. Smooth the top with a spoon and bake for 10 minutes at 400F after 10 minutes lower the heat to 350F and bake for 30-35 minutes or until toothpick comes out clean. Let it cool for 15 minutes.