Grease and flour two 9x5x2 inch loaf pans. Preheat oven to 350 oF. Beat 1/2 c butter in large bowl until smooth and creamy. Add 3/4 c brown sugar, granulated sugar and vanilla. Beat until light and fluffy. Blend in pumpkin. Add eggs, one at a time, beating well after each addition. Mix together 2 1/2 c flour, baking soda, baking powder, cinnamon and nutmeg. Stir into pumpkin mixture. Fold in 1 c of pecans and raisins. Spoon batter into pans. With fork, mix remaining butter, brown sugar, flour and pecans. Sprinkle one-half of mix evenly over each loaf; pat down lightly. Bake about 50 minutes or until a cake tester (or toothpick) inserted in center comes out clean. Cool in pan 10 minutes then remove from pan to rack to cool completely. Makes 2 loaves, 24 servings, 255 calories/serving.