Ingredients:

  • 3 cups (450g) peeled and finely diced Granny Smith or Honeycrisp apples
  • 2 tbsp (25g) granulated sugar
  • 1 tsp (2g) ground cinnamon
  • 1 tbsp (15ml) lemon juice
  • 1/2 cup (115g) unsalted butter, softened
  • 3/4 cup (150g) granulated sugar
  • 2 large eggs, room temperature
  • 1 tsp (5ml) vanilla extract
  • 1 1/2 cups (190g) all-purpose flour
  • 1 tsp (4g) baking powder
  • 1/2 tsp (3g) salt
  • 1/2 cup (120ml) sour cream
  • 1/2 cup (65g) all-purpose flour
  • 1/2 cup (45g) rolled oats
  • 1/2 cup (100g) packed light brown sugar
  • 1/2 tsp (1g) ground cinnamon
  • 6 tbsp (85g) cold unsalted butter, cubed

Instructions:

  1. Preheat the oven to 350°F (175°C). Grease a 9x9 inch square baking pan and line it with parchment paper.
  2. In a medium bowl, toss the finely diced apples with lemon juice, 2 tbsp granulated sugar, and 1 tsp cinnamon. Set aside to macerate.
  3. Cream together the softened butter and 3/4 cup granulated sugar until pale and fluffy. Beat in the eggs one at a time, then stir in the vanilla extract.
  4. Whisk together the flour, baking powder, and salt. Alternately add the dry ingredients and the sour cream to the butter mixture, stirring until just combined.
  5. In a separate bowl, combine the crumble flour, rolled oats, brown sugar, and cinnamon. Rub the cold cubed butter into the mixture using fingers or a pastry cutter until pea-sized clumps form.
  6. Spread the cake batter evenly into the prepared baking pan.
  7. Spoon the spiced apples over the batter, pressing them lightly into the surface.
  8. Scatter the oat crumble generously over the top and bake for 50 minutes or until a toothpick comes out clean.