Preheat your oven to 350°F. Grease an 8-inch cake pan with cooking spray or line the bottom with parchment paper.
In a large bowl, mix the flour, sugar, salt, and baking soda. Add the olive oil, water, lemon juice, and vanilla extract, stirring until just combined. Gently fold in the blueberries.
Pour the batter into the prepared cake pan. Bake for 35-40 minutes, or until a toothpick inserted in the center comes out clean. Let the cake cool completely in the pan before frosting.
For the frosting, beat the cream cheese and butter together until smooth. Gradually add the powdered sugar until fully combined. If the frosting is too thick, add a bit of water; if too thin, add more powdered sugar.