Preheat oven to 350 degrees F. Grease 2 small (8 x 4 x 3-inch) loaf pans.
Combine all streusel ingredients in a food processor. Process until nuts are coarsely chopped. Set aside.
Combine cake mix, instant pudding, sour cream and oil in a large bowl. Beat with electric mixer for 30 seconds. Add eggs, one at a time, beating well after each addition. Beat for 2 minutes.
Divide 1/2 of the batter between the 2 pans, spreading out evenly. Sprinkle 1/4 of the streusel filling on top of batter in each pan. Divide the remaining batter on top of the 2 pans. Top each with remaining streusel.
Bake for 50-60 minutes, or until toothpick inserted in the center of each cake comes out clean.
Remove from oven and cool for 5 minutes. Remove cakes from pan and cool completely on a rack.
Mix glaze ingredients, using only enough cream to make a thick but pourable mixture. Drizzle over cakes.
Makes 2 loaf cakes.