In a large mixing bowl, combine: milk, water, sugar, butter and yeast. Stir to combine. Add in egg and whole wheat flour. Stir in all purpose flour. Dough will be thick. Turn out onto a floured surface and knead until smooth and elastic about 7 minutes. Alternatively, knead with the dough hook on your stand mixer for about 5 minutes. Cover and allow to raise for about an hour.
Prepare a muffin tin (possibly 2) with muffin wrappers. If you are not going to use muffin wrappers, grease the cups very well. Once the dough is risen, turn out onto a floured surface and knead for a minute or two. In a small bowl, melt butter for the topping. In another small bowl, stir together sugar and cinnamon for the topping.
Tear off a small ball of dough and roll it in the melted butter, then in the cinnamon and sugar. Put three sugar/cinnamon covered balls into each muffin cup. Repeat until all the dough is used.
Cover with a clean towel and allow to raise for another hour.
Preheat oven to 350 degrees. Bake muffins for 18-20 minutes. Allow to cool and enjoy.