Cake:
Toast pecans in 1/4 cup butter in 300 degree oven about 20 minutes, stirring frequently and being careful to not overcook. Oven temperatures vary, be careful as an overcooked pecan loses its flavor. Sift baking powder, flour and salt; cream the 1 remaining cup of softened butter, gradually adding sugar. Blend eggs in one at a time. Add dry ingredients alternately with milk, beginning and ending with dry ingredients and mix well. Stir in vanilla and 1 1/3 cups toasted pecans. Bake in 3 (9-inch) greased and floured layer-cake pans at 350 degrees 25 to 30 minutes, or until light brown.
Icing:
Combine softened butter, approximately 1/2 sugar and vanilla, mixing well. Add the other half of sugar, adding as little milk as neccessary to reach a nice spreading consistency. Ice layers, top and sides; sprinkle with remaining nuts.