Preheat oven to 350 degrees F. Spray 9x13" baking dish with cooking spray. Set aside.
In large bowl, cream together the butter and sugar until light and fluffy.
Add eggs, one at a time, beating after the addition of each, then add vanilla.
In a small bowl, combine flour, baking soda, cinnamon, and salt.
Add half of flour mixture to wet ingredients, then the sour cream, then rest of flour mixture.
Fold in the apples.
Pour into prepared baking dish, smoothing out to the edges.
To make the crumb topping, in a small bowl, combine the sugar, flour, cinnamon, and butter and mix until it resembles coarse crumbs.
Sprinkle over the cake batter and bake in preheated oven 35 minutes, or until golden brown and set.
Let cool at least 10 minutes.
Make the glaze by combining the sugar, vanilla, and cream and mix until smooth.
Drizzle over the cake and serve warm.
Enjoy!