Blueberry Sourdough Discard Coffee Cake
Transform leftover sourdough starter into a flavorful coffee cake, perfect for breakfast or an afternoon snack, featuring sweet blueberries and a crumbly streusel topping.
Ingredients
For the Streusel Topping
- 6 tbsp flour (plain/all purpose) for texture
- 6 tbsp Demerara Sugar adds sweetness and crunch
- 5 tbsp unsalted butter softened for moisture and richness
- 2 tsp ground cinnamon plus extra for sprinkling over cake
- pinch salt enhances flavor
For the Cake
- 2 cups flour (all-purpose / plain) for structure
- 1.5 tsp baking powder provides leavening
- 0.5 tsp baking soda helps with leavening
- 1 tsp ground cinnamon contributes to flavor
- 0.25 tsp salt balances sweetness
- 1 cup sugar sweetness
- 1 stick unsalted butter softened for moisture and richness
- 2 large eggs binding agent
- 1 cup sourdough starter unfed / discard adds moisture and flavor
- 0.25 cup whole milk adds moisture
- 1 tsp vanilla extract for flavor
- 2 cups fresh or frozen blueberries divided, adds sweetness and moisture
- 2 tbsp demerara sugar to sprinkle, adds crunch
- 1 cup powdered sugar for glaze
- as needed lemon juice adds tartness
- 1 tsp vanilla extract or paste for flavor
Instructions
Preparation
- Start by preparing the streusel topping. In a bowl, combine the flour, Demerara sugar, softened butter, cinnamon, and a pinch of salt. Mix until it resembles coarse crumbs and set aside.
- Preheat the oven to 340°F (170°C). Grease a 9-inch square baking pan or line with parchment paper.
- In a large mixing bowl, sift together the dry ingredients: all-purpose flour, sugar, baking powder, baking soda, cinnamon, and salt.
- Add the softened butter, eggs, sourdough starter, milk, and vanilla extract to the dry ingredients. Beat until the mixture is smooth and creamy.
- Spread half of the prepared batter evenly into the bottom of the pan. Sprinkle half of the blueberries over the batter, followed by some Demerara sugar. Dollop the remaining batter on top.
- Distribute the streusel topping over the second layer of batter and add the remaining blueberries. Sprinkle extra Demerara sugar and cinnamon over the top.
Baking
- Bake for about 50 minutes to an hour. Tent with aluminum foil if the top browns too quickly.
- Check for doneness by inserting a toothpick; it should come out clean or with a few moist crumbs.
- Allow the cake to cool in the pan for about 20 minutes before transferring it onto a wire rack to cool completely.
Glazing and Serving
- Mix powdered sugar with lemon juice in a small bowl until you reach a drizzling consistency. Adjust lemon juice as needed.
- Slice the cooled cake and serve. It can be enjoyed plain or topped with whipped cream, custard, or ice cream.
Notes
Ensure butter is room temperature for easier blending. Fold blueberries gently into the batter to prevent breaking. For more cinnamon flavor, add extra to the batter or streusel. If using frozen blueberries, do not thaw them before using. Allow the cake to cool completely before glazing to keep icing on top.