Preheat the oven to 350 degrees. Spray or grease your pan for baking. Set it aside.
In a small bowl, combine the flour, baking soda, and salt. Set this aside.
In another bowl, add the softened butter and granulated sugar. beat this for a minute or 2 until the butter is light and soft. To this add in the lemon zest, juice, eggs, Greek yogurt, and buttermilk.
This time only mix to combine. Last is the dry ingredients. Add them and mix to combine.
Pour into your prepared pan. Place in the oven and bake for 50-55 minutes.
Remember that with whole grains, you need to underbake it just slightly. This will keep the cake from drying out with the whole grains in it.
Remove it from the oven. Let it cool in the pan for about 5 minutes. I don't let it sit in the pan for too long or it will get stuck. Then gently run a knife around the edges and turn it out onto your cooling rack. Turn it to make sure the top is facing up.