01 -
Preheat the oven to 175°C. Line a 23 cm round cake tin with baking parchment and grease lightly.
02 -
In a medium bowl, whisk together flour, baking powder, baking soda, cinnamon, and salt. Set aside.
03 -
In a large mixing bowl, beat softened butter and granulated sugar until pale and fluffy. Add eggs one at a time, incorporating fully before the next. Mix in vanilla extract.
04 -
Add half the flour mixture to the butter mixture and mix briefly. Add sour cream, blend gently, then add remaining flour mixture. Mix just until incorporated. Fold in chopped apples.
05 -
In another bowl, combine flour, cinnamon, and salt. Add cold cubed butter and rub it into the dry ingredients until coarse crumbs form. Stir in brown sugar and granulated sugar.
06 -
Spread cake batter evenly into the prepared tin. Sprinkle the crumb topping uniformly over the batter.
07 -
Bake at 175°C for 55–60 minutes, or until a toothpick inserted into the centre comes out clean. Allow to cool in the tin for 15 minutes, then transfer to a wire rack.
08 -
In a small saucepan over medium heat, melt butter. Add brown sugar, cinnamon, milk, and a pinch of salt. Stir continuously until sugar dissolves completely and mixture thickens slightly, about 3 minutes. Remove from heat and let cool to a pourable consistency.
09 -
Once the cake is cooled to room temperature, drizzle the cinnamon apple sauce over the top before serving.