1 c. butter, room temperature
2 c. sugar
4 eggs
5 c. all purpose flour
5 tsp. baking powder
1 tsp. salt
1 c. buttermilk
4 c. fresh blueberries
1 tbsp. lemon zest, finely minced (optional)

Preheat oven to 350 degrees. Grease two 9 x 5 inch loaf pans or one 12 cup bundt pan. Using electric mixer, cream butter with sugar in large bowl. Add eggs one at a time, beating well after each addition. Combine flour, baking powder and salt in another bowl. Add to egg mixture alternately with buttermilk, beginning with dry ingredients. Stir in blueberries and lemon zest. Divide batter between 2 bread pans or put all into bundt pan. Bake until tester inserted in centers comes out clean, about 1 1/4 to 1 1/2 hours. Cool in pans on rack.