Mix together the demerara sugar, cinnamon and nutmeg and sprinkle over the muffins. Bake in the oven for 20-25 minutes until golden brown and springy to the touch.
Make the streusel topping. In a small bowl, whisk together the chopped pecans, sugar, salt and cinnamon ... divide it evenly among the tops of the muffins. Really press it into the muffin batter ...