Apple Coffee Cake with Crumble Topping and Brown Sugar Glaze

I made this for breakfast this morning. I have been wanting to try this recipe for quite some time after reading the numerous positive comments this recipe has received on foodnetwork.com. We agree with those positive comments--this cake is really delicious.

Cake:
½ cup (1 stick) unsalted butter
1 1/2 cups (11 ¼ ounces) 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 (8 ounces) sour cream
1 teaspoon pure vanilla extract
2 cups peeled, cored and chopped apples (about 2 medium apples)
Crumble Topping:
1/2 cup (3 ¾ ounces) 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 (3 ¾ ounces) packed light brown sugar
1/2 teaspoon vanilla extract
2 tablespoons water
Directions
Preheat the oven to 350 degrees F. Lightly grease a 13 by 9-inch pan or spray with nonstick baking spray.

In a large bowl, cream together ½ cup butter and 1 ½ cups brown sugar until light and fluffy. Add the eggs one at a time, beating after the addition of each. In a separate bowl or on a piece of parchment, sift together the flour, baking soda, cinnamon, and salt. Add to the wet ingredients, alternating with the sour cream and vanilla. Fold in the apples. Pour into the prepared pan, spreading out to the edges.

To make the topping, in a bowl, combine the sugar, flour, cinnamon, and butter, and mix until it resembles coarse crumbs. Sprinkle the topping over the cake and bake until golden brown and set, 30 to 40 minutes. Remove from the oven and let cool on a wire rack for at least 10 minutes.

To make the glaze, in a bowl, combine the sugar, vanilla, and water and mix until smooth. Drizzle the cake with the glaze and let harden slightly. Serve warm.