Name: Sourdough Cosmic Brownies Recipe
Prep time: 15 min
Cook time: 35 min
Total time: 3 h 50 min
Cuisine: American
Ingredients: 150 g All Purpose Flour; 380 g White Sugar; 65 g Cocoa Powder; 3 g Salt; 3 g Baking Powder; 125 g Semi-Sweet Chocolate Chips; 130 g Butter, melted; 2 Large Eggs (about 70 g each; if using small eggs add 3); 5 g Vanilla Extract; 120 g Sourdough Starter (active or discard); 130 g Heavy Whipping Cream; 250 g Semi-Sweet Chocolate Chips; 100 g Mini M&Ms or candy coated chocolate chips

Jump to Recipe· 4.2 from 77 reviews

If you have a craving for a rich, fudgy treat that’s also a bit unexpected, you’re going to love this Sourdough Cosmic Brownies Recipe. Combining the tangy charm of sourdough starter with the decadent chocolate and colorful crunch of mini M&Ms, these brownies bring an exciting twist to a classic favorite. The sourdough starter doesn’t just add a subtle depth of flavor but also lends a wonderfully moist and tender crumb that elevates these Cosmic Brownies to a whole new level of deliciousness. Trust me, once you try this recipe, these brownies will become a beloved staple in your baking repertoire.

Ingredients You’ll Need

A square metal pan lined with parchment holds a rich, dark brown baked brownie layer with a slightly rough texture and some small uneven spots. Above it, on a white marbled surface, there is a pink mixing bowl filled with smooth, glossy dark chocolate-like batter with a gold whisk inside. Next to it, a small white bowl is filled with colorful candy-coated chocolate pieces in bright blue, green, red, orange, and yellow. To the right of the pan, two silicone spatulas, one white and one blue, rest on the surface. Photo taken with an iphone --ar 4:5 --v 7

Gathering the perfect ingredients is the first step to baking stellar brownies. Each component in this recipe plays a crucial role, from providing structure and flavor to adding that irresistible texture and color.

150 g All Purpose Flour: Gives the brownies their structure without weighing them down.
380 g White Sugar: Sweetens the batter and creates a moist crumb.
65 g Cocoa Powder: Packs in rich chocolate flavor, making the brownies deeply fudgy.
3 g Salt: Balances sweetness and enhances the chocolate notes.
3 g Baking Powder: Provides just enough lift to keep the brownies soft.
125 g Chocolate Chips (semi sweet): Adds melty chocolate pockets throughout the batter.
130 g Butter, melted: Contributes to a tender texture and rich flavor.
2 Large Eggs: Bind the ingredients and provide moisture.
5 g Vanilla Extract: Lifts the flavor complexity with warm, sweet aromas.
120 g Sourdough Starter (active or discard): Introduces a subtle tang and moist texture, the star of the recipe.
130 g Heavy Whipping Cream: Used for making the luscious ganache topping.
250 g Semi Sweet Chocolate Chips: Creates a glossy, smooth ganache finish.
100 g Mini M&Ms: Adds colorful crunch and a fun cosmic vibe to the brownies.

How to Make Sourdough Cosmic Brownies Recipe

Step 1: Prep Your Pan and Oven

Start by heating your oven to 160°C (320°F). Choose a 9″ x 9″ brownie pan and decide whether to grease it lightly with butter or line it with parchment paper. Both methods prevent sticking, but parchment makes lifting the brownies out easier once baked.

Step 2: Mix the Dry Ingredients

In a large bowl, whisk together the all-purpose flour, sugar, cocoa powder, salt, and baking powder until you have a uniform mixture. Toss the chocolate chips in so they’re fully coated with the flour mixture—this nifty trick stops them from sinking straight to the bottom of the pan during baking.

Step 3: Combine the Wet Ingredients

In a separate bowl, whisk together the melted butter, eggs, vanilla extract, and your sourdough starter. Whether you’re using an active bubbly starter or a discard, it’s important that it isn’t too thick or the batter won’t come together smoothly.

Step 4: Bring Wet and Dry Together

Pour the wet ingredients into the bowl of dry ingredients. Gently fold everything together with a spatula. Don’t worry if the batter feels thick and fudgy—that’s exactly how it should be for extra gooey brownies!

Step 5: Bake the Brownies

Spread the batter evenly in your prepared pan, pushing it out to the edges as needed. Bake for 35 minutes at 160°C (320°F). Around this time, insert a toothpick in the center; it should come out with moist crumbs but not raw batter. The top will have a lovely crackly crust, a telltale sign your brownies are ready.

Step 6: Cool and Prepare the Ganache

Let the sourdough brownies cool for about an hour before moving on. For the ganache topping, place the semi sweet chocolate chips and heavy whipping cream in a microwave-safe jug, warming for about 90 seconds. Stir it thoroughly until the ganache is smooth and shiny, then pour it generously over the brownies.

Step 7: Add the Cosmic Touch

Sprinkle mini M&Ms on top of the warm ganache, then chill the pan in the fridge for at least two hours. This chilling step firms up the ganache, giving the brownies a gorgeous, glossy finish and a fun burst of color that looks just as amazing as it tastes.

How to Serve Sourdough Cosmic Brownies Recipe

Four square brownie pieces sit close together on a white plate, each topped with a smooth, shiny layer of dark chocolate frosting decorated with red, green, blue, yellow, and orange candy pieces scattered unevenly on top and around the plate. The brownies show a thick, moist, and dense texture with bits of chocolate visible inside. In the background, a small bowl filled with colorful candies sits on a white marbled surface, accompanied by three glass cups filled with milk and blue-and-white striped straws, softly blurred to keep focus on the brownies. photo taken with an iphone --ar 4:5 --v 7

Garnishes

For an extra-special touch, add a light dusting of powdered sugar or a drizzle of white chocolate across the ganache. Fresh berries like raspberries or strawberries add a bright contrast to the deep chocolate flavor. And yes, a small scoop of vanilla ice cream on the side makes these brownies borderline magical.

Side Dishes

The beauty of this Sourdough Cosmic Brownies Recipe is that it shines on its own, but if you want to round out your dessert offering, consider serving with a cup of rich coffee or a cold glass of milk. A dollop of whipped cream or a spoonful of fruit compote complements the sourdough tang and chocolate richness beautifully.

Creative Ways to Present

Slice these brownies into fun, star-shaped pieces using cookie cutters for themed parties. You can also layer them in a trifle with whipped cream and fresh fruit for a stunning dessert centerpiece. Wrapping individual pieces in parchment and tying with a ribbon turns these into perfect homemade gifts.

Make Ahead and Storage

Storing Leftovers

Store any leftover sourdough cosmic brownies in an airtight container at room temperature for up to 3 days. This keeps the ganache moist and the brownies chewy. If your kitchen is warm, refrigeration also works well, though it might firm up the ganache.

Freezing

Want to keep these delights longer? Wrap individual slices tightly in plastic wrap and store them in a freezer-safe bag or container. They’ll stay delicious for up to 3 months. Thaw at room temperature when you’re ready to indulge.

Reheating

If you prefer your brownies slightly warm, pop them in the microwave for about 15 seconds. This softens the ganache and warms the center, making the chocolate melty and heavenly. Just be careful not to overheat or the ganache might separate.

FAQs

Can I use sourdough discard instead of active starter?

Absolutely! This recipe is flexible and works wonderfully with either active, bubbly starter or unfed sourdough discard. Just make sure the starter isn’t too thick to ensure even mixing.

What if I don’t have mini M&Ms? Can I use something else?

Definitely! Mini candy-coated chocolates add fun color and crunch, but you can swap them with rainbow sprinkles, chopped nuts, or even white chocolate chips for a different twist.

Why does the sourdough starter improve the brownies?

The sourdough starter imparts a subtle tang and helps create a moist, tender crumb. It enhances depth of flavor and adds a slight chewiness that makes these brownies stand out.

Can I make this recipe gluten-free?

With some adjustments, yes! Substitute the all-purpose flour with a gluten-free blend designed for baking. Keep in mind the texture might vary slightly, but the brownies will still be delicious.

How do I know when the sourdough cosmic brownies are perfectly baked?

Look for a crackly top and use the toothpick test—it should come out with moist crumbs, not wet batter. That balance gives you fudgy, not dry, brownies every time.

Final Thoughts

This Sourdough Cosmic Brownies Recipe is a joyful celebration of flavors and textures—a delightful way to put your sourdough starter to delicious use beyond bread. With every bite, you’ll enjoy fudgy chocolate, a hint of tang, and playful colors that brighten up your day. Don’t hesitate to mix up the toppings or presentation to suit your style; these brownies are a fantastic canvas for creativity. I can’t wait for you to bake a batch and see how they quickly become your favorite cosmic treat!