- For the dough, stir three cups of the flour, sugar, yeast, salt, cinnamon and nutmeg in a stand mixer fitted with the dough hook or in a large mixing bowl. Add the milk, applesauce and eggs and mix just until the dough comes together. Add the butter and continue to mix (the dough will be soft).
- Add the remaining ¼ - ½ cup of flour, as needed while kneading (by hand or on low speed) until the dough feels elastic, about five minutes. Cover and allow the dough to rise until doubled in size, about an hour.
- For the filling, beat the butter, brown sugar, maple syrup, cinnamon, nutmeg, clove and allspice together until smooth. Spread half of this onto the bottom of a greased 9x13 inch baking pan.
- On a lightly floured surface, roll out the dough into a rectangle about 18x10 inches and spread the remaining filling evenly overtop. Sprinkle the diced apples and roll the dough up from the long side. Cut the dough into 12 pieces and place these into the prepared pan, cover and allow to rise for an hour.
- Reheat the oven to 350°F. For the streusel topping, combine the oats, flour, brown sugar, cinnamon and salt. Work in the butter with a spoon until evenly incorporated (the mixture will be crumbly). Sprinkle this over the risen buns and then bake for 45 to 50 minutes, until a rich golden brown. Allow the sticky buns to cool for at least 20 minutes before inverting the whole pan to turn out, or cutting the sticky buns out of the pan one-at-a-time.
The sticky buns are best enjoyed the day they are baked, but can be prepared and placed in the pan and chilled overnight, or frozen and then thawed in the fridge before bringing up to room temperature and baking.