Preheat oven to 350℉. In a medium bowl whisk together flours, baking powder, baking soda and salt. Set aside.
In a large bowl whisk together brown sugar and oil. Add ones egg at time, whisking after each. Add cooked whole grain cereal, buttermilk and vanilla, whisk until well mixed.
Add dry ingredients to wet all at once. Whisk until just combined but completely incorporated. Pour mixture into a 9"x5"x3" loaf pan sprayed with non stick spray. Sprinkle poppy seeds and sesame seeds evenly on top. Bake for 50-60 minutes or until a toothpick comes out clean. Allow to cool completely on a wire rack before removing from pan.
Beat butter by hand in a medium bowl until soft and pliable. Add honey and mix to incorporate.
Cut loaf into thick slices and serve with honey butter.
Cook whole grain cereal such as Red River as per package directions. Allow to cool completely and measure out 1/2 cup. I will generally cook a pot, cool, divide, wrap and freeze for use in this loaf and other baked goods.