Preheat oven to 350 degrees. Spray 3 8-inch round cake pans with nonstick cooking spray*. Sift the flour, baking powder and salt together in a large bowl.
Place butter and sugar in a mixing bowl. Beat on medium/ high speed for about 3-5 minutes, or until fluffy and light. Add the orange zest and vanilla and beat until well combined. Reduce the mixer’s speed to medium, and add the eggs (one at a time, making sure that the last is fully incorporated before adding the next).
Reduce the mixer’s speed to low. Carefully add the flour mixture in parts, alternating with the orange juice. Combine until smooth, being careful not to overbeat.
Divide the batter amongst the 3 cake pans*. Bake for about 20 minutes, or until a toothpick inserted in the center comes out clean. Cool the cakes completely on a cake rack.
*If desired, you can make it a 2 layer cake instead. Just use 2 pans instead of 3.