Generously grease and flour a 9x5-inch nonstick loaf pan; set aside.
In a large bowl beat pumpkin, sugars, 3 egg whites, milk, and oil until well incorporated.
Stir in walnuts and raisins.
In a separate bowl combine cream cheese, 2 tablespoons sugar, and 1 egg white; beat until completely blended and smooth. Make sure the cream cheese is softened beforehand.
Spoon half of pumpkin batter into previously prepared loaf pan.
Top with remaining pumpkin batter.
Bake for 65 to 75 minutes, or until toothpick inserted in the center comes out clean.
Remove from oven and cool in pan for 10 minutes.
Remove from pan and transfer to a wire rack to cool completely.