Prepare streusel in a bowl by melting the butter; then add everything but the cinnamon chips. Mix thoroughly with a fork. Should be wet, but crumbly. Set aside.
In a stand mixer with the paddle attachment, make the cake by beating the butter with the sugars. Add eggs & sour cream. Mix until smooth & incorporated. Add milk & mix together.
In a separate bowl combine both flours, baking powder, baking soda, salt & cinnamon. Gradually add to the wet mixture in the mixing bowl. Fold in cinnamon chips.
Pour batter into a greased baking dish. Sprinkle the top with the prepared streusel & ¼ cup cinnamon chips. Bake at 350*F for 45-50 minutes for an 8x8" square dish (which gets really full) or 30-35 minutes for a 9x13" dish. Check doneness with a knife in the center of the cake. Allow to cool for 10 minutes before cutting & consuming.