Cream butter and sugar together until light and fluffy.
Add eggs and vanilla and blend well.
Add flour and blend well.
Add pureed peaches and buttermilk and blend well.
Fold in peaches and pecans (optional).
Pour batter into a 9x5 loaf pan which has been lined with parchment paper and sprayed with a baking spray like Bakers Joy.
Bake at 350° for 45-55 minutes or just until toothpick inserted in the center comes out clean.
Cool in pan for 5-10 minutes and then remove to cooling rack.
Cool completely before glazing, if desired.