Preheat oven to 350°F. Grease a 9 inch cake tin.
In a medium sized bowl, whisk the brown sugar, oil, eggs, pumpkin puree, grated ginger and vanilla together until fully combined.
In a large bowl, whisk the flour, oats, baking powder, baking soda, salt, cinnamon and nutmeg together until fully incorporated.
Pour the wet ingredients into the dry ingredients and fold until just combined then add the raisins until fully combined.
Pour the batter into the cake tin until ¾ full. If you have pumpkin seeds, you can add them to the top of the cake for added protein, healthy fats and fibre. Bake for 75 to 90 minutes, or until the centre comes out clean when tested with a tooth pick.
Allow the cakes to cool completely in the pans set on a wire rack.