Combine baking powder and 2 3/4 cups flour; sift 3 times.
Add vanilla to milk.
Cream butter until soft and light.
Add sugar gradually; continue creaming until fluffy.
Add egg yolks; beat vigorously.
Add milk and dry ingredients alternately to creamed mixture.
Add pecans to remaining 1/4 cup flour; beat into batter.
Pour into 3 greased and floured layer cake pans.
Bake at 350 degrees for 30 minutes.
Cool; ice with favorite frosting.
Top with pecans, if desired.