Funfetti Sourdough Discard Cookies – The Sweetest Way to Use Up Starter

Funfetti Sourdough Discard Birthday Cake Cookies 🍪🎉

Is there anything more joyful than a cookie that tastes like a birthday cake? These Funfetti Sourdough Discard Cookiestake that nostalgic, sprinkle-packed flavor and give it a clever, sustainable twist—by using sourdough discard!

Perfectly soft in the middle with a gentle chew and glazed to party perfection, these cookies prove that discard baking isn’t just for bread and pancakes. With rainbow sprinkles, a rich vanilla glaze, and a tender bite from the discard, these are a celebration in every bite.


Why I Love This Recipe

Sourdough discard is often overlooked, but in the right recipe, it’s a secret ingredient that adds incredible tenderness and subtle depth. Here, it complements the vanilla-forward flavor and balances the sweetness with a hint of tang. Plus, rainbow sprinkles make everything better.

These cookies are festive enough for a party, yet simple enough to whip up for a Tuesday treat. And if you’re already on the sourdough train, this is a great way to reduce waste and increase joy.


Ingredients

For the Cookies:

  • ½ cup unsalted butter, softened
  • ½ cup granulated sugar
  • ¼ cup brown sugar
  • ¼ cup sourdough discard (unfed works just fine!)
  • 1 large egg
  • 1 tsp vanilla extract
  • 1 ½ cups all-purpose flour
  • ½ tsp baking soda
  • ¼ tsp salt
  • ⅓ cup rainbow sprinkles (jimmies recommended)

For the Vanilla Glaze:

  • ½ cup powdered sugar
  • 1 tbsp milk
  • ¼ tsp vanilla extract
  • Extra sprinkles, for decorating

Ingredient Notes & Swaps

  • Sourdough discard: Make sure it’s unfed but not spoiled. A slightly tangy aroma is perfect.
  • Sprinkles: Stick with jimmies (the long ones) to prevent bleeding. Avoid nonpareils for this.
  • Gluten-free? Substitute with a 1:1 GF flour blend, though texture may vary slightly.
  • Dairy-free? Use plant-based butter and milk in both the dough and glaze.

Step-by-Step Instructions

1. Preheat the Oven

Set your oven to 350°F (175°C). Line a baking sheet with parchment paper or a silicone mat.

2. Cream Butter and Sugars

In a large bowl, beat softened butter, granulated sugar, and brown sugar until light and fluffy—about 2–3 minutes with a hand mixer.

3. Add Wet Ingredients

Mix in sourdough discard, egg, and vanilla extract. Beat until fully incorporated and smooth.

4. Mix Dry Ingredients Separately

In another bowl, whisk together flour, baking soda, and salt.

5. Combine Wet and Dry

Gradually add dry ingredients to wet, mixing just until combined—don’t overmix.

6. Fold in Sprinkles

Gently stir in the rainbow sprinkles using a spatula. Be careful not to over-stir or the colors may bleed.

7. Scoop and Bake

Scoop tablespoon-sized portions of dough onto the prepared baking sheet, spacing 2 inches apart. Bake for 10–12 minutes, or until edges are golden and centers are just set.

8. Cool and Glaze

Let cookies rest on the sheet for 5 minutes, then transfer to a wire rack. Meanwhile, whisk together powdered sugar, milk, and vanilla to make the glaze. Drizzle over cooled cookies and top with extra sprinkles right away.

9. Let Set and Enjoy

Allow glaze to set for 15–20 minutes before serving or storing.


Tips for Success

  • Don’t skip the chill if your dough feels too soft—10 minutes in the fridge will help them hold their shape.
  • Let cookies cool fully before glazing or you’ll end up with a melty mess.
  • Add almond extract (just ¼ tsp) for a true birthday cake flavor boost.
  • Double the batch and freeze the second half—bake from frozen with 1–2 extra minutes.

Storage & Make-Ahead

  • Store cookies in an airtight container at room temperature for up to 4 days.
  • Want to freeze? Baked cookies freeze well for up to 2 months.
  • For make-ahead dough: Scoop and freeze raw dough balls, then bake straight from frozen.

Serving Suggestions & Pairings

Make it a full dessert spread by pairing these cookies with:

Or, serve alongside coffee or a scoop of vanilla ice cream for a treat that tastes straight out of a birthday party.


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Final Thoughts

These Funfetti Sourdough Discard Cookies are a beautiful blend of resourceful baking and pure celebration. If you’ve been throwing away your starter, this might be the recipe that changes your mind forever.

Have you tried these cookies? Share your thoughts, swap-ins, or party stories below—and don’t forget to follow ChefManiac.com for more joyful, creative bakes from my kitchen to yours.