Preheat your oven to 350 degrees, and grease a 9 inch loaf pan. Set aside.
In a medium bowl, stir together the cake flour, baking powder, salt, oats, blended oats, nuts, and chocolate chips. Set aside.
In another medium bowl, beat together the butter and sugar until fluffy. Beat in the eggs, vanilla extract, and sour cream and beat until smooth. Slowly beat in the flour mixture until completely incorporated.
Pour the batter into your prepared pan and spread evenly. Sprinkle the coarse sugar over the top. Bake for 35-40 minutes, or until a cake tester comes out clean. Cool and enjoy!