Preheat the oven to 375°F (190°C). Butter and lightly flour the sides of a 9-inch springform pan and line the bottom with parchment paper.

Place blueberries in a bowl and toss with 1 tablespoon flour and 1 teaspoon lemon juice.

In a mixing bowl, beat sugar and eggs using an electric mixer on high speed until thickened and light in color, about 5 minutes. Mix in sour cream, vegetable oil, vanilla extract, and salt on low speed until just combined. Add 2 cups flour and baking powder and mix until combined. Stir in lemon juice and lemon zest.

Pour half of the batter into the prepared pan and spread evenly. Spread half of the blueberry mixture over the batter. Pour in the remaining cake batter and spread the remaining blueberries on top, pushing them halfway into the batter.

Bake in the preheated oven until the top is browned and a toothpick inserted into the center comes out clean, 35 to 45 minutes.

Remove the outer ring from the springform pan and let the cake cool completely. Dust the top of the cooked cake with confectioners' sugar using a small sifter.