Millionaire Shortbread

Confession: I hate making candy. It’s one of my least favorite things to make in the kitchen. Chocolate, marshmallow, caramel, nougat, fondant, gummies, hard candy, it doesn’t matter what it is, I’m not excited to make it. Because of this, I’ll only willingly do it either during the holidays when everything feels a little more magical and majestic, or when it’s something really, really, really good. Millionaire shortbread falls under the latter for me.

These bars are just the right amount of sweet, with chewy caramel and crumbly shortbread, a hint of bitterness from the dark chocolate and a bite of crunchy sea salt. Occasionally I’ll throw some pecans or peanuts in the caramel, to add more dimension to the party. It’s the perfect balance for a decadent dessert lover, like myself. Like a twix bar’s sophisticated cousin.

FAQs and Science

I don’t have a stand mixer, do I really need one to make the shortbread?

Short answer, no. You can do this with a hand mixer, or just muscle powder with a bowl and spoon. The stand mixer just makes the process easier and much faster.

Why so much corn syrup in the caramel?

Liquid sugars, like corn syrup, help prevent caramel from crystallizing while you cook it. The likelihood of crystallization in caramel increases when it’s stirred, but this recipe is designed to handle that amount of agitation without that problem occurring.

Do I need to use full fat sweetened condensed milk, or can I substitute it for fat free?

Use the full fat stuff. It makes for both a better end flavor and mouth feel.

I prefer milk chocolate to dark, will it ruin anything if I use that instead?

You can absolutely substitute the dark chocolate with milk, I’ve done it before in this recipe. Expect it to be sweeter, of course, and slightly lacking in dimension due to the loss of the bitterness from the dark chocolate, but it’s still perfectly delicious. If you can, use a milk chocolate that has notes of caramel in it to better compliment the rest of the bar.

I really like the idea of the salt on top, but I only have table salt. Can’t I just sprinkle that on the chocolate layer instead?

I wouldn’t recommend it. Flaky sea salt is chunky, and wont dissolve into the chocolate layer quite so easily so you’ll get those defined crunchy bites of salt.

What You’ll Need

• 9×13 inch baking dish
• Parchment paper
• Nonstick baking spray
• Stand mixer and paddle attachment
• Dry measuring cups
• Measuring spoons
• Sieve or sifter
• Whisk
• 4-quart heavy bottom sauce pan
• High heat rubber spatula
• Candy thermometer
• Flat bottomed glass
• Offset spatula or table spoon
• Butter knife
• Chef’s knife
• Cutting board

The Process

Preheat your oven to 350F, on the convection setting if it’s an option, and prepare the 9×13 baking pan. Line the bottom and up two sides of the pan with parchment, then grease the two unlined sides with either butter or nonstick baking spray. In order to cut clean, even bars at the end, you’ll need to be able to remove the entire slab and transfer it to a cutting board, and there’s no hope of doing so without lining it like this. Set the pan aside.

Begin by baking the shortbread layer, it needs to be completely finished before working on the caramel. Whisk together the flour, sifted powdered sugar, and salt in the bowl of a stand mixer.

Melt the butter in the microwave, or on the stove if that’s not an option. Pour in the vanilla extract, then pour the mixture into the stand mixer bowl. Turn the mixer to level one until the butter fully absorbs, about 1-2 minutes. Expect it to be crumbly and dry.

Pause the mixer and scrape down the sides and bottom of the bowl. While the mixer is running on low, add 1 Tablespoon of whole milk at a time until the dough sticks together when pinched. Check after each bit of milk has been absorbed, so you don’t accidentally add too much.

Dump the dough into the prepared baking dish and spread the crumbles as evenly as you can.

Then, take the flat bottomed glass and press the dough into the pan, so a nice, firm crust is formed. Poke the crust all over with a fork, otherwise known as docking the dough. This allows for the steam to escape from the shortbread, making for a more even bake.

Bake the shortbread for 25 minutes, halfway through, until the edges of the shortbread just start to brown. It’s important not to over-bake the shortbread, or it will be tough to bite through.

Once the shortbread crust is fully baked, begin the caramel. Although I’m always a proponent of doing things as efficiently as possible, this is a case where taking your time is the better (and safer) option. This caramel needs constant and complete attention, and once you’re in the thick of it, you wont be able to pause to pull the shortbread out of the oven. Feel free to get the ingredients for the caramel ready to go, but trust me on this one. You’ll be much less stressed being a little bit patient here.

In a heavy bottom 4 quart sauce pan, add in the cut up butter, condensed milk, corn syrup, granulated sugar, and water. Cutting in butter into 1-Tablespoon sized portions will allow it to melt faster and make it easier to whisk. Place the pan over medium high heat and allow it to cook, stirring occasionally.

Once the butter is mostly melted and a homogenous mixture is starting to form, attach the candy thermometer to the side of the pan. If your thermometer doesn’t attach that’s okay, you’ll just need to dip it in to check the temperature every so often as it gets closer to a caramel color later on.

At this point, whisk the caramel constantly, so the bottom wont burn and it will cook evenly. It’s going to boil and start to bubble up, do not panic. As long as you’re using the correct sized pan, it wont boil over the top and you’ll be fine. 

There is a chance of tiny bits of caramel spitting out of the pan as it boils though, so be cautious and keep animals and small children away while you’re cooking. If you’re nervous about it getting onto your hand, wear an oven mitt and long sleeves as you whisk.

Once it reaches 240F, after around 20 minutes or so of cooking and whisking, test the caramel to see if it’s reached soft ball stage. To do this safely and easily, take a small spoonful of caramel and dunk it into ice water.

The ice bath immediately cools down the caramel, so you can touch and mold it with your fingers to gauge the true texture of the caramel. You should be able to form it into a squishy ball. If you can’t, allow it to cook for a bit longer then test the caramel again.

When it passes the softball test, take the caramel off the heat. Whisk in the salt and vanilla extract. The vanilla will cause a rise of steam, so be careful here. Pour the caramel over the shortbread crust, taking care to get it into each corner, and set it aside to cool.

When the caramel has mostly cooled, after an hour or so, it’s time to add the chocolate layer. Place 3 chocolate bars on top of the caramel and give them a few minutes for the residual heat of the caramel to melt them.

Take a large spoon or offset spatula and spread out the melted chocolate. If you’d like to add flaky sea salt, allow the chocolate to set for a few minutes before sprinkling it over top. This way, it wont sink into the middle.

Let the millionaire shortbread to completely cool and set. This could take one hour, or it could take several, it all depends on the temperature of your kitchen. When it’s ready, gently run a butter knife along the unlined sides of the pan to loosen them. Carefully lift the slab out of the pan and transfer it over to a cutting board. Using the chef’s knife, cut the slab into a 6×4 grid, leaving you with 24 pieces.

Store the millionaires shortbread in an airtight container at room temperature for up to 5 days, and enjoy!

Millionaire Shortbread

Bake Time: 350F for 25 minutes
Servings: 24 bars
Total Time: 2 hours 30 minutes
Prep Time: 45 Minutes

Ingredients

Shortbread:

• 2 1/4 cup all-purpose flour
• 3/4 cup powdered sugar, sifted
• 3/4 teaspoon salt
• 12 Tablespoons unsalted butter, melted
• 1/2 teaspoon vanilla extract

Caramel:

• 12 Tablespoons unsalted butter, cut into 12 pieces
• 1 14-oz can sweetened condensed milk
• 1 cup light corn syrup
• 2 cups granulated sugar
• 1/2 cup water
• 1 1/2 teaspoons vanilla extract
• 1 teaspoon salt

Other:

• 3 dark chocolate bars
• Flaky sea salt, optional

Instructions

1. Preheat the oven to 350F, on the convection setting if your oven has one, and prepare the 9×13 inch baking dish. Line the bottom and up two sides with parchment paper. Spray the uncovered shorter sides with nonstick baking spray. Set the pan aside.
2. Start by making the shortbread crust. In the bowl of a stand mixer, whisk together the flour, sifted powdered sugar, and salt.
3. Melt the butter either on the stove top or in the microwave. Mix in the vanilla extract and add it all at once to the dry goods. Turn the mixer on level 3 for 3-4 minutes, until a crumbly dough forms. Add in whole milk, 1 Tablespoon at a time, until the dough holds together when pinched.
4. Dump the dough into the prepared pan, and spread it out as evenly as you can. Using the flat bottom of a glass, press the dough firmly into the pan. Poke the crust with a fork repeatedly, as shown above. Bake the shortbread for 25 minutes or until the edges are just barely starting to brown, flipping halfway through.
5. While the shortbread bakes, get everything ready to begin the caramel layer. To a heavy bottom 4 quart sauce pan, add in the butter, condensed milk, corn syrup, granulated sugar, and water.
6. Once the shortbread has finished baking, place the caramel pan over medium high heat, stirring occasionally as it all begins to melt together. Once the butter has mostly melted, attach a candy thermometer to the side of the pan and begin whisking constantly. Allow the caramel to cook until it reaches 240F, or soft ball stage.
7. When the caramel has reached 240F, carefully remove it from the heat. Pour the vanilla extract and the salt into the caramel, gently whisk them in. Immediately pour the caramel over the baked shortbread. Allow it to set for a minimum of one hour before adding the chocolate layer.
8. Place 3 chocolate bars on top of the caramel and allow them a few minutes to warm. When the chocolate is melted, use an offset spatula or spoon to spread it out over the top of the caramel. Optionally, you could sprinkle on some flaky sea salt at this point.
9. Once the millionaire shortbread has completely cooled and set, run a butter knife along the unlined sides of the pan. Gently lift the entire slab out and transfer it over to a cutting board. Using a chefs knife, cut the shortbread into 24 even pieces, or your desired amount. Store in an airtight container for up to 3 days, and enjoy!

Tips

• Keep the millionaires shortbread away from moisture, as it can cause the chocolate to bloom and caramel to crystallize. If your chocolate becomes fat bloomed, like mine did, it’s still perfectly safe to eat and won’t have an unpleasant mouth feel! It just doesn’t look as pretty. A sugar bloom in the chocolate will taste gritty, though, much like crystallized caramel would.