Heat oven to 350°.

For the topping, mix all ingredients with either your fingers or a fork until crumbly. Set aside.

In a mixing bowl, cream the 1 stick softened butter and 1 cup sugar until creamy. Beat in the eggs, one at a time then add the vanilla extract.

In a separate bowl mix the flour, baking powder, and salt. Add the dry ingredients, in 1/3's, to the creamed butter/sugar mixture, adding milk between additions of flour. Do not over mix. Fold in the blueberries.

Line your muffin tins with cupcake papers and put in batter about 2/3-3/4 full. Top with some of the crumb mixture and bake at 350° for about 25 or nice and browned.