In a medium bowl, cream together butter and sugar, add milk, egg and vanilla.
In a separate bowl, mix flour, cinnamon, baking powder and salt. Add half dry ingredients to wet mixture, stir. Repeat with remaining half of wet mixture. Fold in chopped pecans. Add 2 pecan halves on top of each muffin.
Fill paper lined muffin tins with 1/4 cup of batter. Bake at 350 degrees for about 15 to 20 minutes or until toothpick comes out clean.