Preheat the oven to 450°F and generously grease 2 - 9x4 bread pans.
To peel, core and dice your apples try the following:
Add 3 tablespoons of butter over high heat in a skillet until just brown and then add diced apples for 2 minutes over medium heat. Remove from heat and set aside.
Mix together the dry ingredients (flours, flax seed, baking powder, baking soda, salt, and cinnamon) and set aside.
In a mixer bowl, mix the remaining butter and add the granulated sugar and 1/2 cup of the brown sugar. Beat until fluffy. Add the egg and beat until completely mixed. Add yogurt and sour cream and mix until smooth.
Slowly add in the dry ingredients and mix on slow for 2 minutes.
Fold in the apple chunks.
Divide the batter evenly among the prepared bread pans.
Sprinkle the remaining 1/4 cup of brown sugar on top.
Bake for 20 minutes. Lower heat to 375°F and bake for an additional 40 minutes, or until a toothpick inserted into the center of a loaf comes out clean.
Cool the loaves for 5 minutes in the pans, then turn them out onto a wire rack to cool completely.
** Apples are always on the Environmental Work Group's Dirty Dozen list. Buy organic or know your source.