Grease and line two 8 or 9 inch round cake pans or three 6 inch cake pans and set aside.
Preheat the oven to 350 degrees Fahrenheit.
In a large mixing bowl, whisk together all wet ingredients.
Add in the dry ingredients, making sure to spoon and level the flours, don't scoop right from the bag.
Whisk until smooth.
Give a quick taste and add more orange zest or extract as desired. Do not add more orange juice.
Transfer to your prepared cake pans, trying to fill each as evenly as possible.
For 8 or 9 inch pans, bake for 25-35 minutes or until a toothpick comes out clean, for 6 inch pans, bake for 40-45 minutes.
Remove from the oven and let cool completely.
To make the buttercream, add your softened butter to a bowl or bowl of a stand mixer and beat for 2-3 minutes.
Add in the powdered sugar in 2-3 batches, beating until smooth and creamy.
Add in the orange juice, zest and vanilla and beat until smooth and creamy.
If it is too thin, add more sugar, if it's too thick add in more orange juice or a splash of milk. For a stronger orange flavor, add in more zest or some orange extract.
Once the cake has cooled completely, frost and enjoy!