Place a rack in the center of the oven and preheat to 325 degrees. Coat a bundt pan with cooking spray and set aside.
Cream butter and sugar together until light and fluffy then mix in the eggs one at a time. Make sure to mix each egg in completely before adding the next.
Stir in milk and vanilla and sour cream then sift the dry ingredients on top of the wet ingredients and fold to combine. Cover bowl and let rest in refrigerator for 1 hour.
In a separate mixing bowl, stir together the cream cheese, sugar and egg until completely combined. Set mixture aside. To the bowl of a food processor add walnuts, brown sugar, sugar and cinnamon. Pulse to chop finely. Remove 1/3 cup of the nut mixture for the interior of the cake and set aside. Then add flour, butter and vanilla to remaining sugar and nuts. Pulse again to form the crumb for the top of the cake. Set aside.
When batter has rested for 1 hour, pour 1/2 the batter into a prepared Bundt pan and smooth top. Spread the cream cheese mixture over batter and smooth to the edges. Sprinkle the reserved 1/3 cup of nut mixture over cream cheese then add remaining batter to pan. Smooth batter and bake 40-45 minutes just until firm in the center and light golden brown on top. Remove to a rack to cool for 15 minutes, then invert onto a plate or board to remove from pan and allow to cool completely on a rack.
When cake is completely cool, stir together powdered sugar and milk for the glaze. Drizzle glaze over top of cake and press reserved topping crumble into wet glaze and allow to set. Slice and serve!
One Last Thing
To add another dimension to your cake, swirl in half a cup of seedless fruit jam!