PREHEAT oven to 350 degrees F. Grease and flour 12 cup Bundt pan.
COMBINE brown sugar, cinnamon and allspice in a small bowl.
Cut in butter with pastry blender or two knives until mixture is crumbly.
COMBINE flour, cinnamon, baking soda, and salt in a medium brown.
Beat granulated sugar and butter in large mixer bowl until light and fluffy.
Add eggs one at a time, beating well after each addition.
Add pumpkin, sour cream, applesauce, and vanilla extract; mix well.
Gradually beat in flour mixture.
SPOON half of batter into prepared pan.
Sprinkle streusel over batter, not allowing streusel to touch the sides of the pan.
Top with remaining batter. Make sure batter layer touches edges of pan.
BAKE: for 55-60 minutes or until wooden pick inserted in cake comes out clean.
Cool for 30 minutes in pan on wire rack.
Invert onto wire rack to cool completely. Drizzle with Glaze.
COMBINE 1 1/2 cups sifted powdered sugar and 2 to 3 tablespoons of orange juice or milk in a small bowl; stir until smooth.
(Optional) I added chopped pecans to the glaze.Pumpkin Bundt Cake with brown sugar streusel