Ingredients

For the Cake:

  • 2 cups all-purpose flour
  • 1 teaspoon baking powder
  • 1/2 teaspoon baking soda
  • 1/2 teaspoon salt
  • 1 teaspoon ground cinnamon
  • 1/4 teaspoon ground nutmeg
  • 1/2 cup unsalted butter, softened
  • 3/4 cup granulated sugar
  • 1/4 cup pure maple syrup
  • 2 large eggs
  • 1 teaspoon vanilla extract
  • 3/4 cup sour cream
  • 1/4 cup whole milk

For the Apple Layer:

  • 3 medium apples (Granny Smith or Honeycrisp), peeled and diced
  • 2 tablespoons granulated sugar
  • 1 teaspoon ground cinnamon
  • 1 tablespoon all-purpose flour

For the Maple Crumb Topping:

  • 1/2 cup all-purpose flour
  • 1/2 cup old-fashioned rolled oats
  • 1/3 cup packed brown sugar
  • 3 tablespoons pure maple syrup
  • 1/4 teaspoon salt
  • 1/4 teaspoon ground cinnamon
  • 4 tablespoons cold unsalted butter, cubed

For the Maple Glaze (optional):

  • 1 cup powdered sugar
  • 3 tablespoons pure maple syrup
  • 2-3 tablespoons milk or cream
  • Pinch of salt

Instructions

Prepare the Pan and Oven:

  1. Preheat oven to 350°F (175°C).
  2. Grease a 9-inch springform pan or 9×9-inch square baking pan with butter and lightly flour.

Make the Apple Layer:

  1. In a medium bowl, toss diced apples with 2 tablespoons sugar, 1 teaspoon cinnamon, and 1 tablespoon flour. Set aside.

Make the Crumb Topping:

  1. In a bowl, combine flour, oats, brown sugar, salt, and cinnamon.
  2. Add maple syrup and mix until combined.
  3. Add cold butter cubes and use your fingers or a pastry cutter to work the butter into the mixture until it resembles coarse crumbs with some larger pieces. Refrigerate while making the cake.

Make the Cake Batter:

  1. In a medium bowl, whisk together flour, baking powder, baking soda, salt, cinnamon, and nutmeg.
  2. In a large bowl, cream together softened butter and granulated sugar until light and fluffy (about 3-4 minutes).
  3. Beat in maple syrup, then add eggs one at a time, followed by vanilla extract.
  4. In a small bowl, whisk together sour cream and milk.
  5. Alternately add the flour mixture and sour cream mixture to the butter mixture, beginning and ending with flour mixture. Mix just until combined.

Assemble and Bake:

  1. Spread half the cake batter in the prepared pan.
  2. Evenly distribute the spiced apples over the batter.
  3. Dollop remaining cake batter over apples and gently spread (it’s okay if it doesn’t cover completely).
  4. Sprinkle the crumb topping evenly over the surface.
  5. Bake for 45-50 minutes, or