Preheat oven to 375 degrees F. Lightly spray or grease a 13x9-inch oblong baker.
In a large bowl, combine 1 1/2 cups of the cake mix, the flour and the yeast. Stir well.
Add the beaten eggs and the warm water. Stir for 2 minutes.
Pour batter into prepared pan, spreading it out evenly. Top with the pie filling.
In a separate bowl, combine the remaining cake mix and the melted butter to make the streusel--you may have to use a tablespoon or 2 of regular flour here if the mixture looks too "pasty"--mine did. You want a consistency that will break apart into crumbs, and this should be a bit on the dry side but still pliable.
Top the cake batter with the crumbs, making a nice, even layer. Add nuts, if using. Sprinkle with the 2 tbs of sugar.
Bake at 375 degrees F for 30-35 minutes or until crumbs are beginning to get golden brown and a toothpick inserted in the center of the cake comes out clean.
Cool cake completely on a rack.
Mix all glaze ingredients and drizzle over cooled cake.