Think of this Millionaire’s Shortbread as like a high-quality scratch-made Twix bar. Buttery shortbread is topped with golden dulce de leche and chocolate glaze, balanced to perfect proportions for every bite.
These bars remind me so much of a Twix bar, only being homemade and all, they are clearly a million times better.
(hehehe…get it? A million? Okay, I’ll stop).
Seriously though, these are soooooooo good.
The layers and ingredients involved are simple, but the end result is truly more than the sum of its parts.
Why This Recipe Is So Great
Totally spot-on proportions: I did multiple rounds of recipe testing to get the proportions perfectly balanced, which makes ALL the difference for how it tastes. I’ve made a lot of bar desserts on this blog, like these Cookie Dough Cheesecake Bars and my Chocolate Peanut Butter Marshmallow Squares, and I’ve learned that if something has too much chocolate, not enough filling, or something else out of whack, you don’t get that harmoniously balanced bite.
Only 7 ingredients: Millionaire’s shortbread is a 3-layer bar that only calls for 7 ingredients total, which is pretty darned good in terms of simplicity. It’s amazing how a dessert can be so richly flavorful and delicious but also so minimal.
You can make it ahead, and it travels well: It’s always nice to make food ahead of time so you can grab and go when you’re ready, and this recipe will hold beautifully in the fridge until you’re ready for it. You can even freeze it too.
Insanely delicious: Arguably the most important thing, these millionaire’s shortbread bars are crazy good, and one of my absolute favorite recipes on the blog. Because the bar has THREE elements with the chocolate, caramel, and shortbread, you get a ton of different textures and flavors that play off each other in a harmonious way.
This dessert is truly a perfectly balanced trifecta! You can see above that the thickest layer is the shortbread, which is intentional because it’s the least sweet, then there’s a generous but not too thick layer of dulce de leche, with a thin layer of rich and buttery chocolate on top, that compliments the other two layers without stealing the show.
How to Make It Step by Step:
Plan the Dulce de Leche:
Before you get started, you need to plan how you’ll come up with the dulce de leche for the middle layer. Sometimes you can find it at the store, but usually you have to make your own from sweetened condensed milk. I do this for my Banoffee Pie too.
The safest way is to pour two cans of sweetened condensed milk into a double boiler setup, and let it cook gently for 3 hours, until thick and caramelized.
I’ve included a quicker but riskier method in the recipe box, if you want to go that route, but I recommend planning ahead and doing the safe way.
Make the Shortbread Layer:
While that cooks, work on the shortbread. Much like my butter swirl Shortbread Cookies, this shortbread will have a more crunchy than soft texture.
Beat softened butter around the bowl of a stand mixer with the paddle attachment, then beat in sugar, and an egg yolk:
Note that you CAN use a hand mixer here, but if you have one, the stand mixer is better.
Add all-purpose flour to the bowl:
Mix the flour in until a crumbly dough forms, scraping down the sides as needed:
Press the shortbread dough into a parchment-lined 9×13 metal baking pan, using your fingertips:
Believe me, it’s easiest to press out with your fingers versus something like a spatula.
Prick the dough all over with a fork:
Bake for about 20 minutes, until the shortbread is golden brown on the edges:
Let the shortbread cool for about 15 minutes.
Add the Dulce de Leche:
Once the sweetened condensed milk has turned into thick, caramelized dulce de leche, spread it evenly on top of the cooled shortbread:
Refrigerate the bars to chill the dulce de leche slightly.
Add the Chocolate Layer:
Finally, melt together some dark chocolate chips and butter and spread that over the dulce de leche:
Refrigerate the bars for an hour to firm up the chocolate, then use the parchment paper to lift the bars out onto a cutting board.
Then it’s really easy to cut into whatever shape you’d like:
Add Salt to Make it Pop
While totally optional, I think a sprinkling of specialty sea salt on top is incredible here, to contrast the sweetness:
The bars can be kept at room temperature for up to 3 days. Or, they can be refrigerated for 1 week, or frozen for up to 2 months.
The bars will freeze beautifully for up to 2 months, just make sure it’s stored in an airtight container because the caramel and chocolate will easily absorb off flavors from the freezer.
You don’t want the bars to be too cold when you try to cut them. As the recipe states, only refrigerate the bars for 30 minutes for the caramel, and an hour for the chocolate to harden. Then, run a sharp knife for a minute under hot water to warm it up, then dry it with a clean kitchen towel, and slice.
For the Shortbread:
- 1/2 cup granulated sugar
- 1.25 cups unsalted butter softened (2.5 sticks)
- 1 large egg yolk
- 2.5 cups all purpose flour (356g by weight)
For the Dulce de Leche:
- 2 14-ounce cans sweetened condensed milk
For the Chocolate Glaze:
- 6 oz dark chocolate chips (60 to 70% cacao) (170g by weight)
- 1/2 cup unsalted butter cut into cubes
- sea salt for garnish optional
- Plan the Dulce de Leche: If you can find dulce de leche at the store, you may use that instead, but usually you have to cook your own from cans of sweetened condensed milk. The safest way: Place the sweetened condensed milk in a double boiler setup, by setting a glass heatproof bowl on top of a saucepan with two inches of simmering water. Make sure the water doesn't touch the bottom of the bowl. Cook for 3 hours, until thick and butterscotch colored, stirring every hour. You may need to refill the water once or twice. Let cool.The impatient, riskier way: You can cook the sweetened condensed milk in a nonstick saucepan over medium heat for about 15-20 minutes until thick and caramelized, but you MUST stir constantly with a spatula, or it will burn. Let cool.
- Preheat the oven to 350 degrees F.
- For the shortbread: it is best to use a stand mixer if you have one, but this may all be done with a hand mixer as well. In a stand mixer fitted with the paddle attachment, spread the butter around the bowl by mixing for about 10 seconds on medium. With the mixer still on, pour in the sugar, and beat until the sugar and butter are blended. Briefly beat in the egg yolk until incorporated, then mix in the flour, scraping down the sides of the bowl as needed, until a crumbly dough forms.
- Line a 9×13 inch metal baking pan with parchment paper, then press the dough out evenly using your fingertips. Prick the dough all over with a fork, and bake for 20-22 minutes, until lightly golden brown. Let the shortbread cool completely on a wire rack, about 15 minutes.
- Spread the dulce de leche evenly on top of the shortbread layer, then refrigerate for 30 minutes.
- For the chocolate layer: In a heatproof bowl, combine the dark chocolate chips and butter, and microwave in 30 second intervals until it's almost smooth. Err on the side of microwaving less, so you don't risk overheating the chocolate. I pull it out when the chocolate chips are almost melted, and usually if I keep stirring for a minute, the residual heat will melt it to a smooth consistency. Pour the mixture over the chilled dulce de leche layer and spread it evenly with a spatula. Refrigerate for an hour until the chocolate glaze hardens.
- Once the bars have chilled, cut into squares and serve. Enjoy!
Nutrition is estimated using a food database and is only intended to be used as a guideline for informational purposes.
Post updated with new photos and writing in November 2020. Originally published June 2011.