Preheat oven to 425 degrees, F. Sift together flour, sugar, baking powder and salt. Beat together milk, beaten egg, butter and lemon zest. Mix pears and nuts into flour mixture. Gently stir milk mixture into dry ingredients. Batter should be lumpy, not smooth. Do not over mix.
Spray muffin pans with nonstick spray. Fill muffin cups 2/3 full. Bake at 425 degrees F for 20 to 25 minutes, until tops are browned. Remove from pan immediately, and serve warm.
Tip: Bake in mini muffin pans and bake 425 degrees F for 15 minutes.