Sourdough Cinnamon Roll Blondies
If cinnamon rolls and cookie bars had a baby, it would be these blondies. They’re buttery and golden with a warm cinnamon swirl laced into each bite. Soft in the center, crisp at the edges, and perfectly sweet without being over the top. Top with an easy cream cheese glaze to give them that classic cinnamon roll finish! I can't stop eating these, and I know you won't either!
Equipment
- 9x9 baking pan
- Parchment paper
- Measuring cups and spoons
- 1 Large mixing bowl
- 2 medium mixing bowls
- Whisk
- Spatula
- Hand mixer (optional)
- Kitchen scale optional
- Butter knife or toothpick to swirl blondies
Ingredients
Blondie Batter:
Wet Ingredients:
- 1/2 cup (113g) unsalted butter, softened
- 1/2 cup (100g) brown sugar, packed
- 1/2 cup (100g) white granulated sugar
- 2 large eggs room temperature
- 1 teaspoon vanilla extract
- 1/3 cup (75g) sourdough starter 100% hydration
Dry Ingredients:
- 1 1/2 cups (180g) all-purpose flour
- 2 teaspoons cornstarch
- 1/2 teaspoon baking powder
- 1/2 teaspoon ground cinnamon
- 1/2 teaspoon sea salt
Cinnamon Swirl Paste:
- 3 Tablespoons (42g) unsalted butter, melted
- 1/4 cup (50g) brown sugar, packed
- 2 Tablespoons (25g) granulated white sugar
- 2 teaspoons ground cinnamon
- 1/2 teaspoon sea salt
Cream Cheese Glaze:
- 1 oz (28g) cream cheese, softened
- 1/2 cup (60g) powdered sugar
- 1 Tablespoon (15g) cream
- 1/4 teaspoon vanilla extract
Instructions
Prep Your Pan:
- Line a metal 8x8 or 9x9 inch pan with parchment paper, leaving overhang on the sides. Lightly grease the parchment. A metal pan is crucial for even baking. Look at my list of tools above for the one I use.
Cream the Butter & Sugars:
- In a large mixing bowl, beat the softened butter, brown sugar, and granulated sugar together with a whisk or hand mixer for 2–3 minutes, until light, smooth, and fluffy.1/2 cup (113g) unsalted butter, softened, 1/2 cup (100g) brown sugar, packed, 1/2 cup (100g) white granulated sugar
Add Wet Ingredients:
- Add the eggs and vanilla extract. Whisk until just combined, be careful to not overbeat or your blondie will be gummy. Stir in the sourdough discard and whisk again briefly until smooth.2 large eggs, 1 teaspoon vanilla extract, 1/3 cup (75g) sourdough starter
Mix Dry Ingredients:
- In a separate bowl, whisk together the flour, cornstarch, baking powder, cinnamon, and salt. Fold this mixture into the wet batter using a rubber spatula until just incorporated and no dry streaks remain. The batter will be thick and scoopable. I want to remind you again not to overmix at this stage- if you do, you won't like how your blondie comes out. We want to just incorporate not over mix.1 1/2 cups (180g) all-purpose flour, 2 teaspoons cornstarch, 1/2 teaspoon baking powder, 1/2 teaspoon ground cinnamon, 1/2 teaspoon sea salt
Make the Cinnamon Swirl Paste:
- In a small bowl, mix together the melted butter, brown sugar, white sugar, cinnamon, and flour until a thick, spreadable paste forms. Set this aside.3 Tablespoons (42g) unsalted butter, melted, 1/4 cup (50g) brown sugar, packed, 2 Tablespoons (25g) granulated white sugar, 2 teaspoons ground cinnamon, 1/2 teaspoon sea salt
Assemble the Blondies:
- Spread the blondie batter evenly into the prepared pan and smooth the surface with a spatula. Drop 1 teaspoon spoonfuls of the cinnamon swirl paste all over the top of the blondie, spacing them out. Use a butter knife or skewer to gently swirl it through the top layer. Try not to overdo it or you’ll lose the ripple. You want to see a nice cinnamon sugar ribbon throughout the blondie when done correctly. See below for visuals on how to do this.
Chill the Blondies:
- Cover blondie with plastic and transfer the entire assembled pan to the refrigerator for 20–30 minutes. This step prevents the edges from puffing too high and keeps the swirl defined. DON'T SKIP THIS STEP.
Overnight Ferment Option:
- Allow blondies to rest overnight in refrigerator and bake in the morning if you desire to let them ferment overnight.
Bake Blondies:
- Preheat your oven to 325°F (163°C). Remove blondies from refrigerator and uncover. Bake the blondies for 30-40 minutes. The edges should be golden, and the center should look set but slightly soft. A toothpick inserted near the center should come out with a few moist crumbs, not raw batter.
Cool Blondies & Glaze:
- Let blondies cool fully in the pan on a wire rack — at least 1 hour. You can also refrigerate to help them set up. While blondies cool, whisk together the glaze.
- Transfer cream cheese, powdered sugar, and cream to a small mixing bowl. Whisk together or beat with hand mixers until icing is smooth and has a drizzle like consistency.1 oz (28g) cream cheese, softened, 1/2 cup (60g) powdered sugar, 1 Tablespoon (15g) cream, 1/4 teaspoon vanilla extract
- Drizzle icing over cooled blondies and allow icing to set about 20 minutes. Once icing has set, cut blondies into 9 even squares. Enjoy your Sourdough Cinnamon Roll Blondies!
- Yields 9 blondies
Notes
How to Store:
Room temperature- Store tightly covered at room temperature for up to 3 days.
Refrigeration- Store in an airtight container for up to 5 days in refrigerator.
Freezing- For longer storage, freeze slices before icing individually wrapped in plastic for up to 2 months. Remove from freezer and allow to come to room temperature before icing.