Preheat oven to 350F
Line 2x 8" cake pans with parchment paper and grease with cooking spray
Whisk flour, baking powder, and salt.
In another large bowl, beat sugar, butter, lemon zest until combined.
Add oil and beat until creamy.
Add eggs, one at a time, beating well after each egg.
Add vanilla, and mix thoroughly.
Slowly add dry ingredients and mix on medium-low until just a few dry streaks remain.
Add Milk and beat until incorporated.
Pour batter evenly into both cake pans, and smooth the tops.
Bake until toothpick test comes out clean, approx 18-20 minutes.
Invert on wire rack and let cool completely.