For the topping, in a small bowl stir together the 3 tablespoons flour, the brown sugar, and the 1/4 teaspoon cinnamon. Cut in the 2 tablespoons butter until mixture resembles coarse crumbs. Stir in chopped walnuts or pecans; set aside.

In a medium bowl stir together the 1 1/2 cups flour, the granulated sugar, baking powder, the 1/2 teaspoon cinnamon, the ginger, baking soda, and salt. Cut in the 1/4 cup butter until mixture resembles coarse crumbs.

In another medium bowl combine the egg and buttermilk or sour milk. Add egg mixture all at once to the flour mixture. Stir just until moistened (batter should be lumpy).

Spoon half of the batter into the prepared muffin cups, filling each one-third full. Top with half of the topping, the remaining batter, and the remaining topping.

Bake in a 400°C oven for 15 to 18 minutes or until golden  brown. Cool in muffin cups on a wire rack for 5 minutes. Remove muffins from muffin cups; serve warm.