Mill the 1 1/3 cup (250g) soft white wheat berries. Set aside.
Preheat the oven to 350°F. Prepare the baking dish by spraying with cooking spray, I use avocado oil. You can also use parchment paper.
In a small saucepan on the stove on low, melt the 1 stick (1/2 cup) butter.
In a stand mixer with the paddle attachment (or in a large bowl with the hand mixer) add the melted butter, 1 cup brown sugar, 2 slightly beaten eggs, and 1 1/2 tsp vanilla extract. Mix to combine.
Mash the 3 large or 4 medium bananas in a small mixing bowl using a fork, lumpy is fine. Add the bananas to the wet ingredients in the stand mixer and mix to combine.
In a medium mixing bowl add all of the fresh milled flour (250g) 1 tsp baking soda, and 1/2 tsp salt. Mix to combine.
Add the dry ingredients to the wet ingredients in the stand mixer and mix until combined. If using the optional nuts, now is the time to add and mix together.
Pour the batter into the greased or parchment paper lined baking dish until it's evenly spread. Bake for 45-50 minutes or until a toothpick inserted in the center comes out clean. Put the coffee cake on a cooling rack to cool completely.