Preheat oven to 325°.

Toss washed, drained blueberries with 1/4 cup flour, set aside.

Sift remaining flour with baking powder and salt, set aside.

Separately in mixing bowl, cream butter and sugar together with hand or stand mixer.

Add eggs, one at a time, beating well after each addition.

Add vanilla and beat until fluffy.

Fold dry ingredients (by hand) into batter until well blended.

Gently stir in berries.

Pour into greased and floured 10" tube pan.

Sprinkle with 1 tablespoon sparkling white sugar or turbinado sugar.

Bake 1 hour and 15 minutes or until cake is golden brown and tests done.

Cool cake in tube pan for 10 minutes.

Use a sharp knife to carefully separate cake from the edges of the pan and around the tube in the middle.

(If it's a 2-piece tube pan - also use the knife to separate the the cake from the bottom of the pan.)

Carefully remove the cake from pan and cool on a baking rack.