This sourdough blueberry crumb cake, made with sourdough discard, 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!
Raise your hand if you love cake for breakfast?! Inspired by the classic coffee crumb cake we all know and love, I’ve created this delicious sourdough version to enhance any breakfast, brunch, or snacking situation. More flavor is packed into every bite with a few simple, but noteworthy upgrades.
And because you know I love a good time saving tip, I’ve included my secret weapon for incredible make-ahead desserts (frozen crumble topping) guaranteed to wow your guests at a moment’s notice.
Sourdough Blueberry Crumb Cake: A Few Upgrades
Butter? Oil? Sour cream? What about berries? I wasn’t sure what direction to take this cake at first. Most crumb cake recipes are very similar. But after several tests, including one major flop I wish to eradicate from my memory, I’ve settled on the following 3 recipe upgrades and proud of it!
1.) Salted Butter
If you’re not baking with salted butter, you’re really missing out. I’ve been using salted butter almost exclusively these days, and it makes all the difference in the world especially for cakes, frostings, and chocolate chip cookies.
Also, for a nice touch, I like to lightly brown the butter before adding to the batter. I did this by accident when first testing this recipe, and it was so yummy, I decided to keep it.
2.) Leftover Sourdough Starter (Discard)
Baking with leftover sourdough discard (the stuff you remove and discard when when feeding it), is one of the best ways to get creative with something you’d otherwise throw away.
As long as it’s been recently fed, smells yeasty (not like gym socks), and doesn’t have any dark liquid on top, it will add a wonderful depth of flavor to this crumb cake. Paired with tangy sour cream, the texture becomes rich and decadent too.
Tip: For best results, use leftover 100% hydration starter. This type of starter is fed with equal parts flour and water by weight, and has a consistency similar to thick pancake batter. If you need a sourdough starter, you can create one here (it takes about 7 days and up to two weeks).
3.) Make-Ahead Crumble Topping
This is THE BEST time-saving tip: freeze the crumble topping ahead of time!
Just take any crumble topping recipe (it doesn’t even have to be mine) and store the rubbly bits in a ziplock bag. Use directly from the freezer when ready to assemble desserts like apple crumbles, peach crisps, pies, cakes, etc. It will last in the freezer for several months and there’s no need to let the crumbles come to room temperature before using.
My Thoughts On This Cake…
This sourdough blueberry crumb cake is sweet, fluffy, tangy, juicy…. and I’m telling you, that lightly browned salted butter is just to-die-for.
Also, fyi: the blueberries are mixed into the crumble topping, instead of folded throughout the batter. This way, they won’t sink to the bottom, and you’ll get a burst of warm, blueberry goodness in every bite!
Finally, your best bet is to make this cake fresh and serve it on the same day. The prep takes about 15 minutes from start to finish, and the frozen make-ahead crumbles shaves off even more time.
Enjoy it for brunch, overnight guests, holiday gatherings, weekend treats- the list goes on!
PS: I did test an overnight version of this recipe, one where you would refrigerate the batter and bake the whole thing the following day. But I wasn’t happy with the results. The texture was really chewy. Probably needs more liquid to survive the overnight! If you want to test it out, let me know.Print
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!
Notes & Tips:
- For best results, use leftover 100% hydration starter. Its batter-like texture is the perfect match for this crumb cake. If you’re using a thicker, low hydration starter you will have to add more liquid to the cake batter, such as milk. Otherwise the cake might become too dry.
- Weigh your ingredients for best results! Alternatively, be sure to spoon and level the flour into measuring cups to avoid over packing, and thus a denser cake.
- When adding the crumble topping and blueberries, make sure to evenly cover the surface of the batter, especially the corners. Otherwise, the batter will puff up in certain spots, which could lead to uneven baking.
For the Blueberries
- 1 heaping cup of fresh blueberries
- Powdered sugar, plus more to serve
- 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
- 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)
- 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
- 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.
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