Preheat oven to 350°F. Spray three 6-inch (or two 8-inch) round cake pans with nonstick spray. Line with parchment paper and spray again.
Whisk together flour, baking powder, and salt. Set aside.
Combine sugar, oil, eggs, lemon extract, zest, and lemon juice. Mix on medium speed with an electric mixer until smooth.
Add half of flour mixture and half of the milk. Mix until just blended. Repeat with remaining flour and milk.
Divide batter evenly among cake pans and bake 22-25 minutes, or until golden and a toothpick inserted into the center comes out clean. Let cakes cool in pans for 5 minutes, then transfer to a wire rack to cool completely.