This is an easy and delicious cake with the flavour of gingerbread. When storing, do not cover tightly, or the top will become very moist instead of nice and crunchy. Serve plain or with whipped cream.
Preheat the oven to 180C. Grease and flour an 20x30cm baking dish.
In a large bowl, mix together the oil, 1 cup sugar and molasses until well blended. Beat in the egg. In a separate bowl, stir together the flour, cinnamon, nutmeg, ginger, bicarb soda and salt.
Remove 2 tablespoons of the flour mixture and toss with blueberries to coat. Stir the remaining dry mixture into the wet ingredients alternately with the buttermilk, mixing after each addition. Carefully stir in blueberries. Pour the batter into the prepared pan and sprinkle remaining white sugar over the top.
Bake for 35 to 40 minutes in the preheated oven, until a toothpick inserted into the center comes out clean.