Preheat the oven to 350°F. Grease a 8 x 4 x 2 inch loaf pan with 1 teaspoon of the butter.
In the bowl of an electric mixer, combine the butter, oil, and sugar. Cream the mixture until smooth. Sift the flour, spices, baking soda, baking powder and salt and set aside. Add the egg to the creamed mixture and mix until incorporated. Add the sifted flour mixture, about 1/2 cup at a time until all is incorporated and the batter is smooth. Fold in the zucchini, walnuts and lemon zest. Pour into the prepared pan and bake for 55 to 60 minutes or until golden brown and when a knife inserted in the center comes out clean. Remove from the oven and cool for 10 minutes before serving.
Serve the bread, warm, with butter.
Makes: one loaf