Brown Butter Snickerdoodle Blondies with Cinnamon-Sugar Top

Why You’ll Love This Recipe

• Buttery, toasty depth from real brown butter—no shortcuts.
• Classic snickerdoodle tang thanks to cream of tartar and baking soda.
• Irresistible crackly cinnamon-sugar top with chewy centers and crisp edges.
• One bowl for the batter and ready in under 90 minutes, cooling included.

Grocery List

• Produce: None
• Dairy: Unsalted butter; eggs
• Pantry: All-purpose flour; light brown sugar; granulated sugar; vanilla extract; ground cinnamon; cream of tartar; baking soda; fine or kosher salt; parchment paper

Full Ingredients

Blondie Batter

• 3/4 cup (170 g) unsalted butter
• 1 cup (200 g) packed light brown sugar
• 1/2 cup (100 g) granulated sugar
• 1 large egg, at room temperature
• 1 large egg yolk, at room temperature
• 2 tsp pure vanilla extract
• 1 1/2 cups (180 g) all-purpose flour
• 1 1/2 tsp cream of tartar
• 1/2 tsp baking soda
• 1/2 tsp fine salt (or 3/4 tsp Diamond Crystal kosher salt)
• 1 tsp ground cinnamon

Cinnamon-Sugar Top

• 1/4 cup (50 g) granulated sugar
• 1 1/2 tsp ground cinnamon
• Pinch of fine salt

Optional Finishing

• Pinch of flaky sea salt, for sprinkling after baking

Step-by-Step Instructions

Step 1: Prepare the pan and oven

Heat the oven to 350°F (175°C). Line an 8-inch (20 cm) square metal baking pan with parchment, leaving a 2-inch overhang on two sides to form a sling for easy removal. Lightly grease the parchment.

Step 2: Brown the butter for deep flavor

In a light-colored saucepan, melt the butter over medium heat. Continue cooking, swirling occasionally, until the butter foams, the milk solids turn golden brown, and it smells nutty, 5–7 minutes. Immediately scrape all butter and browned bits into a large heatproof bowl. Cool until warm but not hot, about 5–10 minutes.

Step 3: Make the cinnamon-sugar topping

In a small bowl, stir together 1/4 cup (50 g) granulated sugar, 1 1/2 tsp ground cinnamon, and a pinch of salt. Set aside.

Step 4: Build the glossy base

Add the brown sugar and 1/2 cup (100 g) granulated sugar to the warm brown butter. Whisk vigorously for 30 seconds. Add the egg, egg yolk, and vanilla; whisk until the mixture is thick and glossy, about 1 minute. This helps create that shiny, crackly top.

Step 5: Combine dry ingredients

In a separate bowl, whisk the flour, cream of tartar, baking soda, salt, and 1 tsp cinnamon. Add the dry mixture to the wet ingredients and fold with a spatula just until no dry spots remain. The batter will be thick.

Step 6: Pan, top, and swirl

Scrape the batter into the prepared pan and smooth the top with an offset spatula or damp spoon. Sprinkle the entire surface evenly with the cinnamon-sugar mixture. For a faint marbled look, lightly drag the tip of a butter knife in short S-shaped motions across the top—do not mix in.

Step 7: Bake and cool for clean slices

Bake until the edges are set, the top is crackly, and a toothpick inserted 1 inch from the edge comes out with a few moist crumbs (not wet batter), 22–26 minutes. If using a glass pan, add 3–5 minutes. Cool in the pan on a rack for 30 minutes, then lift out using the parchment and cool 10–15 minutes more before cutting into 16 squares. Sprinkle with a pinch of flaky sea salt if using.

Pro Tips

• Use a metal pan for the best caramelized edges; glass runs cool and often needs extra time.
• Whisking the sugars into warm brown butter and beating in the egg until glossy encourages that signature crackly top.
• Do not overbake—pull them when the center still looks slightly soft for fudgy-chewy bars.
• Weigh your flour if possible (180 g). Too much flour makes cakey blondies.
• Let the bars cool before slicing; setting time gives clean edges and the perfect chew.

Variations

• White Chocolate Cinnamon Chip: Fold in 1/2–3/4 cup white chocolate or cinnamon baking chips before spreading in the pan.
• Chai-Spiced: Replace the 1 tsp cinnamon in the batter with 1 1/2 tsp chai spice blend; keep the cinnamon-sugar topping as written.
• Party Pan: Double the recipe for a 9×13-inch pan. Bake at 350°F (175°C) for 28–33 minutes.

Storage & Make-Ahead

Store cooled blondies in an airtight container at room temperature for up to 3 days, or refrigerate for up to 5 days. Freeze tightly wrapped bars for up to 2 months; thaw at room temperature. To prep ahead, brown the butter up to 3 days in advance and refrigerate; rewarm until fluid before mixing. Batter can be covered and refrigerated up to 24 hours; let stand 20–30 minutes at room temperature, then spread, top, and bake (add 2–3 minutes to the bake time).

Nutrition (per serving)

Approximate per bar (1 of 16): 220 calories; 10 g fat; 31 g carbohydrates; 2 g protein; 1 g fiber; 18 g sugars; 140 mg sodium.