In a large mixing bowl, cream sugar & butter. Add eggs, one at a time, beating well. Add vanilla.
Combine the flour, baking powder, & salt; add to creamed mixture alternately with milk. Beat just until combined.
Fold in pecans.
Pour into three greased 9" round baking pans. Bake at 350°F for 25-30 minutes. Cool for 10 minutes before removing from pans; set aside & cool completely.
For frosting, beat the cream cheese, butter, powdered sugar, & vanilla. Beat in enough milk to achieve spreading consistency.
Spread frosting between layers, inserting toothpicks to stabilize layers.
Frost top & sides of cakes. Sprinkle with pecans. Store in refrigerator.
Recipe by Food Askew at http://foodaskew.net/2010/07/toasted-butter-pecan-cake/