Easy Sourdough Apple Cake with Crumble Topping

Prep Time:30

Cook Time:20

Equipment

Kitchen scale

Ingredients

For the Cake

½ cup (120g) sourdough discard
6 tbsp (90ml) neutral oil (such as vegetable oil, canola, or light olive oil)
½ cup (100g) granulated sugar
¼ cup (50g) light brown sugar
2 large eggs
2 tbsp (30g) milk
1 tsp vanilla extract
1⅓ cups (170g) all-purpose flour
1 tsp baking powder
¼ tsp baking soda
1 tsp ground cinnamon
¼ tsp salt
2 cups (275g) peeled, diced apples (Granny Smith or Pink Lady work great)

For the Crumble Topping

½ cup (60g) all-purpose flour
¼ cup (50g) light brown sugar
1 tsp ground cinnamon
¼ tsp salt
3½ tbsp (50g) unsalted butter, cold and diced

For the Maple Glaze

½ cup (60g) powdered sugar
2 tbsp (30ml) pure maple syrup
½ tbsp (7g) melted butter

Instructions

Preheat the oven to 350°F (175°C). Lightly grease a 9-inch round cake pan and line with parchment paper. Let the parchment overhang the edges for easy lifting.
In a large mixing bowl, use a hand mixer or stand mixer with the paddle attachment to beat the granulated sugar, brown sugar, and oil together until smooth. Add eggs one at a time, beating well after each addition. Mix in the sourdough discard, milk, and vanilla extract until combined.
In a separate bowl, whisk together the flour, baking powder, baking soda, cinnamon, and salt.
Add the flour mixture to the wet ingredients and mix until just combined. Do not overmix.
Peel and dice the apples into small, even chunks (about ½-inch pieces). Fold them into the batter using a spatula. The mixture will be thick and lumpy. That’s exactly what you want.
Make the crumble topping: In a small bowl, stir together the flour, brown sugar, cinnamon, and salt. Add the cold diced butter and use your fingers or a pastry cutter to work it into coarse crumbs.
Pour the batter into the prepared pan and smooth the top. Sprinkle the crumble topping evenly over the batter.
Bake for 40–50 minutes, or until a toothpick inserted in the center comes out with just a few moist crumbs. If the top browns too quickly, tent loosely with foil for the final 10 - 15 minutes.
Let the cake cool in the pan for 15 - 20 minutes before removing. Move to wired rack to cool completely.
Make the glaze: In a small bowl, whisk together the powdered sugar, maple syrup, and melted butter until smooth and pourable. Drizzle over the cooled cake.

Notes

For a mild flavor that lets the apples shine, use sourdough discard that’s relatively fresh (ideally from the same day or the day before). Older discard will still work, but it may add a more noticeable sour note. If you prefer, you can also use active sourdough starter.
For the most accurate and consistent results, use a kitchen scale to measure your ingredients (especially flour and sourdough discard). Measuring by weight ensures the right balance of moisture and structure, and helps avoid a dry or dense cake.

Servings: 8 slices