In a bowl stir together the flour, the oats, the brown sugar, the baking powder, the salt, the cinnamon, the dates, and the walnuts and in another bowl whisk together the yogurt, the milk, the butter, and the egg. Stir the yogurt mixture into the flour mixture and stir the batter until it is just combined. Divide the batter among 6 paper-lined 1/2-cup muffin tins and bake the muffins in the middle of a preheated 400°F. oven for 30 minutes.
