· 3/4 cup light brown sugar· 3/4 cup all purpose flour· 2 teaspoons ground cinnamon· 6 tablespoons butter, melted· 1 cup light brown sugar· 1 1/2 tablespoons ground cinnamon· 1 cup all purpose flour· 1 cup butter, room temperature· 1 cup granulated sugar· 2/3 cup light brown sugar· 3 eggs· 1 tablespoon vanilla extract· 3/4 cup sour cream· 1 teaspoon kosher salt· 3 teaspoons baking powder· 1 1/4 cup milk· 3 2/3 cup all purpose flour· 1 cup powdered sugar· 2-3 tablespoons milk
Step 1Preheat oven to 350°F. Coat a 9×13 baking dish with nonstick spray. Set aside.Step 2In a medium bowl prepare the cinnamon filling by whisking together the brown sugar, flour, and cinnamon until combined. Set aside.Step 3To prepare the crumb topping, mix together the melted butter, brown sugar, cinnamon, and flour in a medium bowl until it resembles coarse crumbs. Use your hands to mix to form larger crumb pieces. Set aside.Step 4For the cake, mix the butter, granulated sugar, and light brown sugar in the bowl of your stand mixer fitted with the paddle attachment on medium speed for 2 minutes until light and fluffy.Step 5Add in the eggs, vanilla, sour cream, salt, and baking powder and mix for 1 minute until combined and smooth, scraping the sides of the bowl as necessary.Step 6Turn the mixer to low and add in the flour and milk in alternating portions, beginning and ending with flour. Mix until just combined and smooth, again, scraping the sides of the bowl as necessary.Step 7Spread half of the cake batter into the prepared pan. Sprinkle the cinnamon filling evenly on top of the batter. Carefully spread the remaining cake batter on top of the cinnamon layer.Step 8Evenly sprinkle the crumb topping on top.Step 9Bake for 40-45 minutes, or until the cake is set and a toothpick inserted in the center comes out clean.Step 10Remove cake from oven and place pan on a wire rack to cool completely.Step 11Whisk together the powdered sugar and milk until smooth and drizzle on top of the cooled cake. Or alternately sprinkle with powdered sugar instead of making the icing.