Preheat oven to 350 degrees F (175 degrees C). Grease and flour three 7x3-inch loaf pans.
Mix together pumpkin puree, eggs, butter, buttermilk, and brown sugar in a large bowl until well blended. Combine whole-wheat flour, all-purpose flour, baking soda, salt, cinnamon, nutmeg, cloves, and ginger in a small bowl. Fold flour mixture into pumpkin mixture until just blended. Gently stir in raisins and pumpkin seeds. Pour into prepared pans or muffin cups. Lightly sprinkle tops with raw sugar.
Bake in preheated oven until a toothpick inserted into center comes out clean; about 50 minutes.
