• To prepare the cake
• Preheat oven to 350°.
• Coat 2 (8-inch) round cake pans with cooking spray; line bottoms with parchment paper then spray with a light coat of cooking spray.
• Place granulated sugar and ¼ cup butter in a large bowl. Using hand mixer, beat at medium speed until well blended.
• Add eggs, 1 at a time, beating well after each addition.Lightly spoon 1-¾ cups flour into dry measuring cups, and level with a knife.
• Combine flour, baking powder, and ½ teaspoon salt, stirring well with a whisk.
• Combine greek yogurt, water, banana, and 1 teaspoon vanilla. Add the flour mixture and buttermilk mixture alternately to the sugar mixture, beginning and ending with flour mixture (mix after each addition just until blended).
• Pour batter into prepared pans.
• Bake cake at 350° for 25 minutes or until wooden pick inserted in center comes out clean.
• Cool in pans 10 minutes on a wire rack; remove from pans.
• Peel off parchment paper. Cool layers completely on wire rack.

To prepare frosting:

• Combine cream cheese, 2 tablespoons butter, lemon rind, ½ teaspoon vanilla, and dash of salt in a large bowl.
• Beat with a mixer at high speed until fluffy.
• Gradually add powdered sugar; beat at low speed just until blended.Place 1 cake layer on a plate, and spread with ⅓ cup frosting.
• Arrange blueberries in a single layer over frosting, and top with remaining cake layer. Spread remaining frosting over top and sides of cake.
• Decorate top of cake with more blueberries if desired. Store cake loosely covered in refrigerator.