These shortbread brownies combine two classic desserts into an irresistible bar. The shortbread base is tender and buttery, while the brownie layer is rich, fudgy and decadently chocolatey. 
I’m a big fan of brownies, and these shortbread brownies may be my new favorite. The contrast between a melt-in-your-mouth shortbread crust and a nearly gooey brownie topping is simply irresistible. The shortbread is buttery and not overly sweet — exactly how shortbread should be — while the brownie layer delivers deep dark chocolate flavor and a satisfyingly fudgy texture.
Because the combination is already rich, the recipe keeps sweetness balanced so the chocolate remains the star.
Making Shortbread Brownies
Below are helpful tips and step-by-step instructions to guide you through the recipe.
Start with the shortbread layer. Beat slightly softened butter with sugar, then add the flour, cornstarch and salt. Keep the butter a little cool rather than fully softened — it makes mixing a bit harder but gives the shortbread a better, crumbly texture.
The dough will be crumbly and you may find it hard to fully incorporate all the flour into the butter. Press the mixture into a prepared 8×8-inch (20×20 cm) pan lined with parchment paper (leave an overhang for easy removal). I like to use a sheet of wax paper between my hands and the dough to press it evenly. Prick the top lightly with a fork, taking care not to poke through to the bottom. 
Bake the shortbread on its own for about 16–18 minutes, until the top looks set and the edges are just beginning to turn golden.
While the shortbread bakes, prepare the brownie batter. For a deep chocolate taste without excessive sweetness I recommend 50–70% dark chocolate; 70% yields a richer, less sweet result. If you prefer a sweeter brownie, use semi-sweet chocolate.
- Melt the butter and finely chopped chocolate together in a heatproof bowl. If using a microwave, heat in short bursts (about 45 seconds on medium), stirring between intervals, or melt the mixture in a double boiler. Finely chopping the chocolate helps it melt evenly.
- Allow the mixture to cool until warm but not hot. Whisk in the sugar, eggs and vanilla. If the chocolate is too hot, the eggs can curdle, so let it cool slightly first.
- Sift in the flour, cocoa powder and salt. Cocoa powder can be lumpy, so sifting helps ensure a smooth batter. Stir gently until there are no visible streaks of flour or cocoa.
- Pour the brownie batter over the pre-baked shortbread crust and smooth into an even layer.
Bake the bars for about 22–24 minutes at 350°F (180°C), or until the top is set and a toothpick inserted into the center comes out clean or with a few moist crumbs. Bake time will vary by oven and by how gooey you prefer the brownies.
Pro tip: Let the bars cool completely before slicing so the layers set and you get clean cuts. Use the parchment overhang to lift the cooled slab from the pan, place it on a cutting board, and slice with a thin, sharp knife, wiping the blade between cuts. A table knife usually doesn’t slice the shortbread crust cleanly.
The buttery shortbread and the fudgy chocolate brownie pair beautifully: the crisp, tender crust contrasts perfectly with a rich, almost gooey brownie top, creating a deliciously balanced bar.
Equipment
- 8×8 inch (20×20 cm) pan
Ingredients
Shortbread Crust
- 2/3 cup (150 g) unsalted butter, slightly softened but still cool to the touch
- 1/3 cup (67 g) granulated sugar
- 1 1/4 cup (156 g) all-purpose flour, measured correctly
- 1 teaspoon cornstarch (cornflour)
- 1/4 teaspoon salt
Brownie Layer
- 1/2 cup (112 g) unsalted butter, cut into cubes
- 5 oz (142 g) dark chocolate, finely chopped (50–70% recommended)
- 1 cup (200 g) granulated sugar
- 2 large eggs, room temperature
- 1 teaspoon vanilla extract
- 1/2 cup (63 g) all-purpose flour
- 3 tablespoons (16 g) cocoa powder
- 1/2 teaspoon salt
Instructions
- Preheat oven to 325°F (170°C). Lightly spray an 8×8 inch pan, then line it with parchment paper leaving an overhang. Spraying first helps the paper stay in place.
- Shortbread layer: Beat together butter and sugar until combined. Beat in flour, cornstarch and salt until the mixture is dry and crumbly. Transfer to the prepared pan and press into an even layer using wax paper to help. Prick the top lightly with a fork (several rows of shallow pricks). Bake 16–18 minutes, or until the top appears set and the edges begin to color. Remove from oven.
- Turn oven to 350°F (180°C). Brownie layer: Place butter and finely chopped chocolate in a heatproof bowl and melt either in short microwave bursts (stirring between) or in a double boiler. Let cool until warm, then whisk in sugar, eggs and vanilla. Sift in flour, cocoa and salt, and gently mix until no streaks remain.
- Pour the brownie batter over the baked shortbread crust and gently spread into an even layer. Bake 22–24 minutes at 350°F (180°C), or until the top is set and a toothpick comes out clean or with a few moist crumbs. Cooling time may vary depending on desired gooeyness.
- Cool completely before slicing. Use the parchment overhang to lift the bars from the pan, place on a cutting board, and slice with a sharp knife, wiping the blade between cuts.
Notes
- Butter: Use real butter (not margarine). Salted butter is fine; omit the added salt if using it. Keep the butter slightly cool, not melted.
- Flour: Measure accurately. Spoon the flour into a measuring cup and level off, or weigh in grams for greatest accuracy.
- Chocolate: I prefer 65–75% dark chocolate for balance. Use semi-sweet for a sweeter brownie. Avoid chocolate stronger than 75% to prevent excessive bitterness.
- Storage: Store in an airtight container at room temperature up to 5 days. To freeze, wrap cooled bars tightly and place in a freezer-safe bag or container; thaw in the fridge before serving.
- Nutrition: Nutrition facts are estimates per serving, assuming the pan is divided into 12 equal pieces.