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Close-up millionaire shortbread bar showing pale sandy shortbread crumb, amber caramel layer, and dark satin chocolate top
Luna Hossain

Millionaire Shortbread Bars Recipe

Three-layer bars with a sandy butter shortbread base, silky condensed milk caramel, and a dark chocolate top finished with flaked sea salt — sliced clean every time.
~382 kcal | ~22g fat | ~42g carbs | ~27g sugar | ~5g protein | ~115mg sodium
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Prep Time 20 minutes
Cook Time 30 minutes
Chill Time 2 hours
Total Time 2 hours 50 minutes
Servings: 16 bars
Course: Bars & Brownies
Cuisine: American
Calories: 382
Ingredients Equipment Method Notes

Ingredients
  

  • For the Shortbread Base:
  • - 2 cups 240g all-purpose flour, spooned and leveled
  • - ¾ cup 170g unsalted butter, cold and cut into ½-inch cubes
  • - ½ cup 60g powdered sugar (confectioners sugar), sifted
  • - ¼ tsp 1.5g fine sea salt
  • For the Condensed Milk Caramel:
  • - 1 can 14 oz / 396g sweetened condensed milk, full-fat — not evaporated milk
  • - ½ cup 113g unsalted butter, cut into tablespoon-sized pieces
  • - ½ cup 100g packed light brown sugar
  • - 1 tsp 5ml pure vanilla extract
  • - ¼ tsp 1.5g fine sea salt
  • For the Chocolate Top:
  • - 8 oz 227g bittersweet chocolate (60–70% cacao), finely chopped — use a bar, not chips
  • - 1 tsp 5ml refined coconut oil (neutral-flavored) or unsalted butter
  • For the Topping:
  • - 1 tsp flaked sea salt Maldon or similar large-crystal brand

Equipment

  • Required:
  • Kitchen scale (strongly recommended — gram weights are more accurate than volume for all three layers)
  • 8×8 inch (20×20cm) light-colored aluminum baking pan
  • Parchment paper — two strips with overhang
  • Food processor, stand mixer with paddle attachment, or large mixing bowl and fingertips
  • Medium heavy-bottomed saucepan (for the caramel)
  • Wooden spoon or heat-resistant silicone spatula
  • Candy thermometer or instant-read thermometer (for caramel temperature verification)
  • Heatproof bowl (for melting chocolate)
  • Offset spatula or back of a spoon (for spreading chocolate layer evenly)
  • Sharp chef's knife
  • Optional:
  • Oven thermometer — recommended; most home ovens run 15–25°F (8–14°C) off and the shortbread base is sensitive to temperature
  • Bench scraper — useful for scoring even bar portions before the final cut
  • Small bowl of warm water — for warming the knife blade between cuts

Method
 

  1. Position oven rack in the middle and preheat to 325°F (165°C), then line an 8×8 inch (20×20cm) light-colored aluminum pan with two overlapping strips of parchment paper leaving at least 2 inches of overhang on all sides, and lightly grease the pan before laying the parchment down.
  2. Whisk together the 2 cups (240g) all-purpose flour, ½ cup (60g) sifted powdered sugar, and ¼ tsp (1.5g) fine sea salt in a large bowl, then add the ¾ cup (170g) cold cubed unsalted butter and rub it into the flour mixture using a food processor (8–10 pulses), stand mixer on low (2–3 minutes), or fingertips until the mixture resembles coarse damp sand with no butter pieces larger than a small pea.
  3. Transfer the mixture to the prepared pan and press firmly and evenly into the base using the flat bottom of a measuring cup, paying particular attention to the corners, then prick the surface all over with a fork approximately 20–25 times spaced 1 inch apart.
  4. Bake at 325°F (165°C) for 18 to 22 minutes until the very bottom edges are pale golden and the top surface is still cream-colored and matte — do not wait for the top to look golden — then transfer to a wire rack and cool completely, approximately 45 to 60 minutes.
  5. Once the base is fully cooled, combine the 1 can (14 oz / 396g) sweetened condensed milk, ½ cup (113g) unsalted butter, ½ cup (100g) packed light brown sugar, and ¼ tsp (1.5g) fine sea salt in a medium heavy-bottomed saucepan over medium heat, stirring continuously from the moment the butter begins to melt.
  6. Cook the caramel over medium heat, stirring constantly and scraping the bottom of the pan with every stroke, for 8 to 12 minutes until the mixture reaches 225–230°F (107–110°C) on a candy thermometer and a small amount dropped into cold water forms a soft pliable ball, then remove from heat and stir in the 1 tsp (5ml) pure vanilla extract.
  7. Pour the hot caramel immediately over the cooled shortbread base, spread to all four corners with an offset spatula, and allow to cool at room temperature for 30 minutes until the surface is firm and tacky but no longer liquid.
  8. Combine the 8 oz (227g) finely chopped bittersweet chocolate and 1 tsp (5ml) coconut oil or butter in a heatproof bowl and melt in the microwave in 30-second intervals at 50% power, stirring between each interval, until completely smooth and fluid — approximately 3 to 4 intervals.
  9. Pour the melted chocolate over the set caramel layer, spread evenly to the edges with an offset spatula using light strokes, then immediately scatter the 1 tsp flaked sea salt evenly across the surface while the chocolate is still fluid and glossy.
  10. Transfer the pan to the refrigerator and chill for a minimum of 2 hours or overnight until all three layers are fully set.
  11. Lift the slab from the pan using the parchment overhang and place on a cutting board, then warm a sharp chef's knife in hot water, dry it completely, and cut into 16 bars using firm downward pressure — rewarming and drying the knife between every single cut.

Notes

- Condensed milk: must be sweetened condensed milk (full-fat) — evaporated milk will not set and the batch cannot be saved.
- Chocolate: use a baking bar at 60–70% cacao, finely chopped — chips contain stabilizers that prevent a smooth melt and even layer.
- Butter: must be cold and cubed for the shortbread base — room-temperature butter produces a dense, bread-like base instead of sandy shortbread.
- Caramel doneness: target 225–230°F (107–110°C) — verify with cold water test; forms a soft pliable ball at correct stage.
- Chilling: minimum 2 hours before cutting — caramel is still soft beneath the surface before then and will collapse under the knife.
- Knife technique: warm the blade in hot water and dry completely between every cut — cold blade shatters the chocolate top.
- Storage: lidded hard-sided container, parchment between layers, room temperature up to 3 days or refrigerator up to 7 days.
- Freeze: wrap individual bars in two layers of plastic wrap, freeze up to 2 months — thaw overnight in refrigerator, add fresh salt flakes after thawing.
- Make ahead: full slab can be made and refrigerated uncut up to 2 days before slicing — layers set more completely overnight and slicing is cleaner.
- Scaling: doubles linearly for all three layers — no leavening in this recipe, so no non-linear adjustment needed. Bake two separate 8×8 pans.
- Altitude: reduce caramel target temperature by 2°F per 1,000 feet above sea level — always verify with cold water test.
- Allergens: contains wheat, dairy. Chocolate may contain soy (check label). Gluten-free adaptation not tested.
- Tip: score the pressed shortbread base into bar portions before baking — the pre-weakened lines align with final cuts and reduce crumbling at the base layer.