Preheat oven to 350°F (175°C). Grease and flour a 9x13 inch baking pan, or line with parchment paper and spray.

In a medium bowl, combine the diced apples, 2 tablespoons brown sugar, 1 teaspoon cinnamon, and lemon juice. Toss to coat evenly and set aside.

In a small bowl, whisk together the 1/2 cup light brown sugar, 1 tablespoon cinnamon, and 1/4 cup melted butter until a thick, crumbly paste forms. Set aside.

In a large mixing bowl, whisk together the all-purpose flour, baking powder, salt, 1 teaspoon cinnamon, 1/4 teaspoon nutmeg, and granulated sugar. Make a well in the center.

In another medium bowl, whisk together the melted butter, milk, eggs, and vanilla extract until well combined.

Pour the wet ingredients into the well of the dry ingredients. Mix with a whisk or spatula until just combined. Do not overmix; a few small lumps are okay. Gently fold in the prepared cinnamon apples.

Pour half of the cake batter into the prepared baking pan and spread evenly. Sprinkle half of the cinnamon swirl mixture over the batter. Carefully spoon the remaining cake batter over the swirl layer and spread gently to cover. Sprinkle the remaining cinnamon swirl mixture on top.

Bake for 50-60 minutes, or until a wooden skewer inserted into the center of the cake comes out clean. If the top browns too quickly, you can loosely tent it with foil during the last 15-20 minutes of baking.

Remove the cake from the oven and let it cool in the pan on a wire rack for at least 20-30 minutes. While the cake cools, prepare the glaze.

In a small bowl, whisk together the powdered sugar, 3 tablespoons milk/cream, and 1/2 teaspoon vanilla extract until smooth and pourable. Add more milk, 1 teaspoon at a time, if a thinner glaze is desired, or more powdered sugar for a thicker glaze.

Once the cake has cooled slightly but is still warm, generously drizzle the vanilla glaze over the top. Allow the glaze to set for a few minutes before slicing and serving.