Using an electric mixer, beat butter until light; beat in honey, egg and pumpkin. Gradually add flour mixture, mixing until just blended. Stir in walnuts, if desired.
Spoon into 12 greased or paper lined 2 1/2" muffin cups. bake at 350° for 25-30 minutes or until a toothpick inserted in center comes out clean.
Remove muffins from pan to a wire rack. Serve warm or at room temperature.