Heat oven to 375 degrees. Grease a square 9-by-9-by-2-inch pan or a round 9-by-1 ½-inch.
Prepare the crumb topping by combining all the ingredients.
Blend flour, Pioneer Granulated Sugar, baking powder, salt, shortening, milk, and egg. Beat for 30 seconds. Carefully stir in the blueberries.
Spread into the pan and sprinkle with the crumb topping.
Bake for 45 to 50 minutes or until a toothpick inserted in the center comes out clean.
While the cake bakes, prepare the glaze by combining all the ingredients until a drizzling consistency.
When the cake is done, drizzle with the glaze and serve warm.