Cinnamon Bake

1 egg 1/2 cup milk 1/2 teaspoon salt 1 cup brown sugar (not packed) 2 Tablespoons melted butter or margarine 1 cup all purpose flour 2 teaspoons baking powder 1/4 cup brown sugar (packed) 1 Tablespoon melted butter 1 teaspoon cinnamon 1/2 cup chopped walnuts Using an electric mixer, beat the first five ingedients till fluffy. Stir flour and baking powder together and add to the mixer. Continue beating just until blended. Pour into a 9" x 9" greased pyrex dish. Mix the last four topping ingredients by hand and sprinkle evenly on top of batter. Bake 375 degrees for 20 to 25 minutes. Test with skewer. Cut into squares when cooled.