1. Preheat over to 350 degrees F.
2. Sift the flour, baking soda, salt, cinnamon, and nutmeg into a large bowl. Mix in the pumpkin, brown sugar, buttermilk, egg and butter until well blended. Pour into a 9x5 inch loaf pan and smooth the top.
3. Bake for 1 hour in the preheated oven, or until a toothpick inserted into the center comes out clean.