Sift flour, baking powder and salt. Set aside.
Cream butter, sugar and vanilla.
Add 2 eggs and blend.
Fold in 1/3 of dry ingredients. Fold in the milk, half at a time alternating with the dry ingredients.
Fold in blueberries.
Pour into a 9 inch pan lined with nonstick foil.
Bake 30 minutes at 350 just to set.
Remove and sprinkle on the crumbs.