In a mixing bowl, blend all-purpose flour, brown sugar, baking soda, baking powder, and sea salt.
Cut in butter until mixture forms pea sized crumbs.
Stir in whole wheat flour and oats. Add buttermilk, using bread hook if available. If mixture is sticky, add in more whole wheat flour, 1 Tablespoon at a time, just until the dough has a smooth, dry surface.
Place dough ball on a lightly floured board and knead 6-7 times, shaping into a loaf. Spray 4”x 8” loaf pan with non-stick spray and place dough in the pan.
Bake at 400 until golden brown, about 45-50 minutes. Test for doneness with metal skewer.
Remove from pan immediately and cool on rack. Let rest for 10-15 minutes before slicing.
