• Preheat oven to 350 degrees F. Grease and flour an 8-inch round cake pan.
• Stir together walnuts, brown sugar and cinnamon. Set aside.
• Mix flour, sugar, baking powder and salt together in a mixing bowl. Stir very thoroughly.
• Add the softened butter to flour mixture and mash with a spoon, coating as much flour as possible. Using fingers or a pastry cutter, cut mixture until it is coarse and mealy like soft bread crumbs (I used fingers).
• Mix together the milk, egg and vanilla. Add to flour mixture and stir (do not beat) until well mixed. It should look a bit like cream of wheat – not that smooth.
• Spread about ⅔ batter into prepared pan. Sprinkle half of nut mixture over batter. Spread remaining batter over nuts, then top with remaining nut mixture.
• Bake on center rack for 25-30 minutes or until done.

Icing

• Cool a bit, then drizzle with icing. To make the icing, mix together the 6 tablespoons powdered sugar and about 1 tablespoon of warm water – just enough to get a smooth consistency. Spoon the icing over the coffee cake or, if the coffee cake is cool, put the icing in a zipper bag, snip a tiny hole off the end of the zipper bag and squeeze it out decoratively.