01 - Preheat the oven to 350°F. Grease and flour a 9-inch round cake pan or line it with parchment paper.
02 - In a medium bowl, whisk together flour, baking powder, baking soda, and salt.
03 - Using an electric mixer or whisk, cream the butter, vegetable oil, and granulated sugar until light and fluffy, about 3 minutes.
04 - Beat in eggs one at a time, mixing thoroughly after each. Incorporate lemon zest and lemon juice until combined.
05 - Alternate adding the dry ingredient mixture and milk to the batter in three additions, beginning and ending with flour mixture. Stir in vanilla extract.
06 - Gently fold the blueberries that have been tossed with flour into the batter to prevent sinking.
07 - Pour batter into prepared pan and smooth the surface. Bake for 38 to 42 minutes until a toothpick inserted into the center comes out clean.
08 - Allow the cake to cool in the pan for 10 minutes before transferring to a wire rack to cool completely.
09 - Whisk powdered sugar with fresh lemon juice until smooth and pourable.
10 - Drizzle the lemon glaze over the cooled cake. Allow the glaze to set before slicing and serving.