Prep the Oven and Pan: Heat oven to 350 F (180 C) and grease and flour a 12-cup Bundt cake pan. Make sure you get all the nooks and crannies.
Prepare the Batter: In a mixing bowl combine the cake mix, eggs, vanilla, lemon extract, oil, and cream cheese. Beat for 2 minutes with an electric mixer at medium speed. Fold the blueberries into the batter and spread in the prepare Bundt cake pan.
Bake and Cool: Bake for 45 to 55 minutes, until a wooden pick or cake tester inserted in the center of the cake comes out clean. Let the cake cool in the pan on a rack for 15 minutes, then carefully turn it out on the rack and cool completely.