Preheat your oven to 350.

In a bowl, whisk 2 1/2 cups flour with baking powder and salt, then set aside.

In another bowl, cream butter and sugars on high speed until light and fluffy.

Add eggs, one at a time, beating until incorporated, then beat in vanilla.

Reduce speed to low, then add flour mixture in three additions, alternating with two additions of sour cream.

In another bowl, toss blueberries and zest with remaining teaspoon flour, then gently fold into batter.

Coat a 12 cup nonstick Bundt pan with cooking spray, then pour batter into bunt pan.

Bake cake on bottom rack of oven until a toothpick inserted into center of cake comes out clean, 60 to 70 minutes.

Cool in pan 20 minutes, then invert onto a rack to cool completely, top side up.

Dust with confectioners' sugar before serving, if desired.

Note: Tossing the zest and berries with some flour, this will help keep the fruit suspended in the batter while the cake cooks. Enjoy!