Preheat oven to 400° F. Weigh or lightly spoon flour into dry measuring cups, level with a knife. Combine flour and next 7 ingredients (through wheat germ) in a large bowl, stirring well with a whisk. Slowly add buttermilk, stirring just until moist. Let sit 15 minutes. Spoon batter into a 9 X 5-inch metal loaf pan coated with cooking spray. Bake at 400° for 40 minutes or until a wooden pick inserted in center comes out clean. Cool in pan 5 minutes on a wire rack; remove from pan. Cool on rack. Slather generously with matcha butter.