Mill the 1 2/3 cup (325g) soft white wheat berries into a fine flour. Set aside.
Preheat the oven to 375°F. Prepare the baking sheet by spraying with cooking spray (I use avocado oil).
Add all of the freshly milled flour and 2 cups sugar to a large mixing bowl. Mix until combined and set aside.
Add the 2 sticks (1 cup) butter, 1 cup water, and 4 tbsp cocoa to a small saucepan. Bring to a boil and then pour over the flour and sugar mixture.
Add the remaining ingredients: 1/2 cup buttermilk, 2 eggs slightly beaten, 1 tsp baking soda, and 1 tsp vanilla. Mix to combine.
Pour into the prepared baking sheet pan. Bake for 15 minutes or until a toothpick inserted in the center comes out clean.