Steps:
Preheat the oven to 350ºF. Cream together butter, lemon zest, and ⅞ cup of sugar until the mixture is light and fluffy.
Add the egg and vanilla, beating until well combined. In the meantime, coat the blueberries with ¼ cup of flour and whisk together the remaining flour, baking powder, and salt.
Gradually add the flour mixture to the batter, alternating with the buttermilk. Gently fold in the blueberries.
Grease a 9-inch square baking pan or a similar-sized pan with butter or non-stick spray. Spread the batter evenly into the pan and sprinkle the remaining tablespoon of sugar over the top. Bake for 35 to 45 minutes, checking for doneness with a toothpick. If needed, return the pan to the oven for a few more minutes. (Note: Baking for an additional 10 minutes may be required.)
Allow the cake to cool for at least 15 minutes before serving.
Enjoy your delightful morning treat!
