1) In a small bowl, stir the streusel topping ingredients together very well until thoroughly combined and crumbly. Set aside.Preheat the oven to 350 F.

2) Combine all of the dry cake ingredients thoroughly, making sure to set any lumps straight.

3) Combine the wet cake ingredients very well in a separate bowl. Stir the wet mixture into the dry ingredients and combine well, but do not over-mix.Gently stir in the blueberries. Lightly oil a 9.5 x 13.5-inch pan and spread the batter into it.

4) Sprinkle the streusel evenly over the cake.

5) Bake for one hour, or until a knife inserted in the center comes out clean. Allow the cake to cool slightly before icing it.To make the icing, begin by removing any lumps from the sugar if necessary. You can do this with your fingers, a fork, or by pouring it through a strainer or sifter. Next, combine all of the icing ingredients together well, stirring with a spoon.When the cake is slightly cooled, drizzle the icing evenly over the top. You can pretend you are Jackson Pollack if you like. Finally, cut the cake and get ready for a serious yum situation.