Preheat the oven to 350 degrees F. Place paper liners in 9 muffin cups and spray with nonstick cooking spray.
In a large bowl, combine the pecans, sugar and flour. Make a well in the center of the mixture.
In a separate bowl, beat the eggs until foamy. Add the melted butter and stir to combine. Pour the egg mixture into the well in the dry ingredients, stirring until moistened.
Spoon the batter into the cups, filling each almost full. Bake until a toothpick comes out clean when inserted in a muffin, about 20 minutes.
This recipe also makes great mini-muffins; just shorten the baking time by 5 minutes.
Recipe adapted from Georgia Cooking in an Oklahoma Kitchen with Trisha Yearwood (c) Clarkson Potter 2008