Preparation

• Position a rack in the center of the oven and heat the oven to 350° F. Lightly butter a 9×2-inch round cake pan. Line the bottom with a parchment round cut to fit the pan, lightly flour the sides, and tap out the excess.
• 在一个中等大小的碗中，将面粉，玉米面，发酵粉，小苏打和盐搅拌直至充分混合。在装有桨叶附件（或手动搅拌机）的立式搅拌机中，将黄油，糖和柠檬皮以中等高的高度搅拌直至充分混合和蓬松，约3分钟。一次加入一个鸡蛋，以中等速度跳动，直到将其混合在一起并与第二个鸡蛋加入柠檬汁（面糊会凝结；不用担心）。使用宽阔的橡胶铲，将一半的干成分，然后是酪乳，然后将其剩余的干成分折叠。将面糊刮入准备的锅中并均匀散开。烘烤15分钟。

Meanwhile, make the topping.

• Combine the blueberries, sugar, and flour in a small bowl. Using a table fork, mix the ingredients, lightly crushing the blueberries and evenly coating them with the flour and sugar. After the cake has baked for 15 min., slide the oven rack out and quickly scatter the blueberries evenly over the top of the cake (discard any flour and sugar that doesn’t adhere to the berries). Continue baking until a toothpick inserted in the center of the cake comes out clean, another 23 to 25 min.
• Let the cake cool on a rack for 15 min. Run a knife around the inside edge of the pan. Using a dry dishtowel to protect your hands, lay a rack on top of the cake pan and, holding onto both rack and pan, and invert the cake. Lift the pan from the cake. Peel away the parchment. Lay a flat serving plate on the bottom of the cake and flip the cake one more time so that the blueberries are on top. Serve warm or at room temperature.