Preheat oven to 350 degrees F. Lightly grease and flour a 9x5x3 inch loaf pan. Place the butter and the sugar in a large bowl. Using a mixer, cream together the butter and sugar until light and fluffy. Mix in syrup, yogurt, cinnamon and nutmeg. Add the eggs, one at a time, beating well after each addition. In a separate bowl, mix together the flour, oatmeal, salt, baking powder and baking soda. Add flour mixture to the butter mixture and stir well. Add apples and mix well. Pour batter into prepared pan. In a small bowl, mix 4 tablespoons of turbinado sugar with 2 tablespoons of cinnamon. Pour in a line down the middle of the batter. Take butter knife and drag it through the cinnamon sugar mixture creating a swirl pattern. Bake in preheated oven for 60 minutes, until a toothpick inserted into center of the loaf comes out clean.