In a large bowl, sift together flour, baking soda, and baking powder. Stir in granola and demerara sugar. Mix in butter with a pastry cutter or use fingers until thoroughly combined. Set aside.
Mix together yogurt and egg in a small bowl. Pour egg mixture into flour mixture and stir well. Knead together lightly with hands to form a round loaf. Place loaf on parchment paper or silpat lined cookie sheet. Take a knife and lightly cut an 'X' on the top of loaf. Bake for 35-40 minutes, or until loaf sounds hollow when tapped on top.
Transfer loaf to wire rack and let cool at least 5 minutes before cutting into slices.
Quick breads are best eaten the day they are made. To store leftovers, place bread in a sealed plastic bag and store at room temperature for up to 3 days.
For longer storage, freeze in a freezer proof bag for up to 3 months.