This sourdough blueberry crumb cake is the perfect treat to make for brunch and weekend breakfasts. With an easy make-ahead topping, browned butter, and a rich sour cream base there’s no way you’ll pass on a second slice! Don’t forget to check out my notes below for best results. Enjoy!
PREPARATION TIME:
- Prep Time: 15 minutes
- Cook Time: 55-65 minutes
- Total Time: 70-80 minutes
Ingredients
For the Blueberries
- 1 heaping cup of fresh blueberries
- Powdered sugar, plus more to serve
Crumble Topping
- 1/4 cup (50g) sugar
- 1/2 cup (100g) light brown sugar
- 1 1/2 cups (180g) all purpose flour, spooned and leveled
- Rounded 1/2 tsp cinnamon (use 1 tsp for more flavor)
- Pinch of fine sea salt
- 8 tbsp or 1 stick (113 g) salted butter, cut into small cubes, cold
Wet Ingredients
- 8 tbsp or 1 stick (113 g) salted butter
- 1 cup (200 g) sugar
- 1 large egg
- 1/2 cup (120g) leftover sourdough starter discard (see note below)
Dry Ingredients
- 2 cups (240 g) all purpose flour, spooned and leveled
- 1 tsp. baking powder
- 1/2 tsp baking soda
- 1/4 tsp fine sea salt
- 1/2 cup (120g) sour cream
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Instructions
- Preheat the oven to 350 F/176 C. Lightly oil an 8×8-inch pan and line with parchment paper. Smooth the bottom and sides of the pan so the paper is flat.
- Add the blueberries to a small bowl. Sift a a tablespoon of powdered sugar over the top and gently toss to combine. This will prevent the berries from sinking into the cake. Set aside.
- To make the crumble topping, add all of the ingredients to a medium-sized bowl. Mix into crumbles using your hands. The butter should be well blended into to the flour; some larger pieces are OK. If using frozen crumble topping, remove it from the freezer now.
- In a small skillet, melt the butter until light golden brown around the edges (you are not fully browning the butter). This will only take a few minutes, but do not walk away from the pan- it will burn quickly! Set aside to cool slightly.
- Meanwhile, using a stand mixer, beat the sugar, egg, and sourdough starter on medium-low speed, about 1 minute. With the machine running, gradually pour in the warm melted butter.
- In a separate bowl, sift the dry ingredients together. Add to the wet ingredients, and mix on low speed until just combined. You should still see specks of flour in the bowl; do not over mix. Add the sour cream and mix until smooth. This technique will give the cake a soft, velvety texture. The batter will be thick.
- Spoon the batter into the pan. In an even layer: scatter 1/2 of the crumbles over the top first, then layer 1/2 of the blueberries on top. Repeat to finish all of the crumbles and blueberries.
- Bake for 55-65 minutes or until a toothpick comes out clean when inserted (I use a dried piece of spaghetti). For me, 60 minutes is the sweet in a shiny metal pan. Please check at the 55 minute mark to see how things are going.
- Cool completely before serving.
- Dust with powdered sugar if you like, and cut into squares.
