In a medium bowl, combine the brown sugar, flour, and cinnamon. Cut in the butter with a pastry blender or two knives until coarse crumbles form. Set aside.
Cake
Preheat the oven to 350˚F. Grease and flour a 12-cup Bundt pan. Set aside.
Whisk together the cake mix, instant vanilla pudding mix, cinnamon, nutmeg, ginger, and allspice. Add the large eggs, whole milk, melted butter, and eggs. Mix on low until combined. Then, beat on medium to two minutes.
Sprinkle half of the cinnamon streusel in the bottom of the pan in an even layer. Spoon half of the cake batter on top and spread it out to cover the streusel. Then, add the remaining streusel and finish with the rest of the cake batter.
Bake at 350˚F for 45-50 minutes or until a toothpick inserted in the center comes out clean.
Allow the cake to cool for 20 minutes. Then, remove it from the pan and let it cool completely on a wire rack.
Glaze
Whisk together the powdered sugar, whole milk, and vanilla. Use a spoon to drizzle the glaze over the cooled cake.
Video
Notes
One: Tightly wrap the cooled cake with plastic wrap and store it for 1-2 days at room temperature. To freezer it, wrap with aluminum foil over the plastic and store it in the freezer for 1-2 months.Two: The streusel on top forms a caramelized crust. You can cut the cake into slices before the top layer hardens. Or, use a serrated knife to cut it, starting at the hole in the center of the cake.