Cake:
1 stick plus 2 teaspoons unsalted butter
1 1/2 cups packed light brown sugar
2 large eggs
2 cups all purpose flour
1 teaspoon baking soda
1 teaspoon ground cinnamon
1/2 teaspoon salt
1 cup sour cream
1 teaspoon pure vanilla extract
2 cups peeled, cored and chopped apples

Crumble Topping:
1/2 cup packed light brown sugar
1/2 cup all purpose flour
1/2 teaspoon ground cinnamon
4 tablespoons unsalted butter, softened

Brown Sugar Glaze:
1/2 cup packed light brown sugar
1/2 teaspoon vanilla extract
2 tablespoons water