Preheat oven to 165°C. Lightly oil and line a 22 cm square baking tray.
Put the oat and walnuts in a food processor and pulse until coarsely ground. Transfer this mixture to a large bowl. Add the flour, baking powder & soda, cinnamon, ginger and mix well.
In another bowl, combine the carrots, syrup, raisins, coconut and vanilla.
Add the carrot mixture to the flour and stir until combined.
Tip the batter into the baking tray and bake for about 45-60 minutes, until the cake is cooked through and golden. Let it cool in the tin for five minutes then turn it out to a wire rack.
When it's completely cool, cut the cake into squares.