Preheat your oven to 350°F (175°C). Grease a 9x13-inch baking pan with butter or non-stick spray to ensure the cake doesn’t stick.

In a large bowl, whisk together 2 cups all-purpose flour, 1 1/2 teaspoons baking powder, 1/2 teaspoon baking soda, 1/2 teaspoon cinnamon, 1/2 teaspoon salt, and 1 1/2 cups granulated sugar until well combined. Stir in 1/2 cup melted unsalted butter, 1 cup sour cream, 3 lightly beaten eggs, and 2 teaspoons vanilla extract. Mix until the batter is smooth and no flour pockets remain. Pour the batter evenly into the prepared pan.

Evenly distribute the finely chopped Granny Smith apples over the top of the batter in the pan. The apples will sink slightly into the batter as it bakes, giving bursts of fruit in every bite. I like to use Granny Smith apples for their tart flavor, but feel free to experiment with your favorite variety.

In a medium bowl, stir together 3/4 cup all-purpose flour, 3/4 cup packed light brown sugar, 1 cup chopped pecans, 1/2 teaspoon cinnamon, 1/4 teaspoon salt, and 1/2 cup melted unsalted butter until well mixed and crumbly. Sprinkle this topping mixture evenly over the apples on the batter.

Place the pan in the preheated oven and bake for 40 to 45 minutes, or until a toothpick inserted in the center comes out clean. Allow the cake to cool slightly in the pan while you prepare the glaze.

In a small saucepan, combine 2/3 cup packed light brown sugar, 2 tablespoons apple cider, and 2 tablespoons unsalted butter. Place over medium heat, stirring until the sugar is dissolved and the butter is melted. Drizzle the warm glaze over the slightly cooled coffee cake. Serve warm or at room temperature. I always make sure to drizzle the glaze generously for a gooey, delicious finish!