This millionaire cake has a buttery shortbread crust, tender brown butter cake layer, and decadent layers of caramel and chocolate ganache.

It’s a dreamy combination that will have you coming back for seconds!

How to Make This Millionaire Cake

Let’s walk through each step of this recipe to make sure it turns out as amazing as possible.

I’ve also shared a video tutorial below.

Step 1: Make the Caramel

Make the caramel filling first so that it can thicken up before it’s spread on top of the cake.

Heat the sweetened condensed milk, butter, brown sugar, and light corn syrup over medium heat in a heavy saucepan.  

Stir frequently until the mixture comes to a gentle boil. Once this happens, turn the heat down to let the caramel simmer.

Continue to stir frequently until the mixture thickens and becomes a medium caramel color (about 5 minutes).  Remove from heat and stir in the vanilla extract and salt.

Pour into a separate container, then set aside to cool to room temperature. If you make this in advance, cover the bowl and store it at room temperature overnight or in the fridge for up to a week.

This is what my caramel looks like once it cools to room temperature.

Step 2: Make the Shortbread Crust

Next, we tackle the shortbread crust. Preheat the oven to 350 F / 175 C and line an 8×8-inch square, metal pan with parchment paper and set aside.

Use a pastry cutter or electric mixer to combine the butter, flour, powdered sugar, and fine salt.

Then press the shortbread into an even layer in the prepared pan and prick the crust thoroughly with a fork.

Bake until the edges are just starting to brown. This usually takes 20-24 minutes and varies based on the type of pan you use and your oven.

Place the pan on a wire rack to cool and keep the oven on for the cake which we’ll bake next!

Step 3: Make the Brown Butter Cake Batter

While the shortbread crust bakes and cools, make the brown butter cake batter following the recipe card at the bottom of this post.

Pour the batter over the shortbread crust in the prepared pan and bake for 36-40 minutes, or until a toothpick comes out with a few moist crumbs.

Set on a wire rack to fully cool before topping. If you want to accelerate the process, place the pan in the freezer for 30 minutes.

Once the cake is fully cooled, gently lift the cake out of the pan using the overhanging parchment paper.

Step 4: Make the Chocolate Ganache

The last step is to make the chocolate ganache! I like to make it as the cake bakes and cools because it needs time to thicken as it cools to room temperature.

Add the heavy cream into a medium-sized bowl and heat it until it just begins to bubble. This can be done in either the microwave (this takes me about 45-60 seconds in my microwave) or a double boiler.

Then pour in the dark chocolate and let the mixture sit for a minute.

After a minute the chocolate should be softened.

Stir the mixture until the cream and chocolate are combined and the mixture is smooth. If any bits of chocolate aren’t fully melted, heat the mixture again for 15 seconds and stir until smooth.

Then mix in the unsalted butter, corn syrup, and fine salt.

Cover with plastic wrap placed flush against the top of the ganache to prevent it from forming a skin, then set aside to cool to room temperature.

If you need to make this topping in advance, it can be covered and stored in the fridge for up to a month.

The ganache should thicken and be scoopable once it reaches room temperature.

If you’re in a rush, pour the ganache into a wide, shallow container to help it cool down faster. Or if you need to make this in advance, it can be covered and stored in the fridge for up to a month.

Step 5: Top the Cake

Once the cake is fully cooled, scoop the room-temperature caramel on top and spread it into an even layer.

Then spread the room-temperature chocolate ganache on top of the caramel.

I did this before removing that cake from the pan and it makes it harder to get out (the caramel and ganache really weigh it down)!! That’s why I recommend removing the cake from the pan before spreading on the toppings.

Add a sprinkle of flakey sea salt, then use a sharp, warm knife to cut into the cake.

Clean the knife after each cut to get perfect slices. Leftover cake can be kept at room temperature for 2 days, or stored in the fridge for up to a week in an airtight container.

Substitutions & Swaps – Shortbread Crust

This recipe uses quite a few ingredients and I know you might not have all of them on hand.

Below are some swaps and substitutions that can be made in this recipe.

• Unsalted Butter – Salted butter can be used in place of unsalted butter, just omit the salt that the shortbread crust recipe calls for.
• Powdered Sugar – This gives the crust the perfect hint of sweetness and makes the crust more stable. You can use granulated sugar in its place if needed, but the texture won’t be quite as smooth.
• AP Flour – A good baking gluten-free flour blend can be used in place of the AP flour in the crust.

Substitutions & Swaps – Cake & Toppings

• Granulated Sugar – You can increase or decrease the amount of sugar by a few Tablespoons based on your preferences.
• Egg Whites – You can also use 2 large eggs in place of the egg whites in this recipe.
• Brown Butter – If you’re short on time and aren’t able to brown your butter, you can use regular, unsalted butter in its place.
• Light Brown Sugar – I prefer using light brown sugar to make the caramel, but you can also use dark brown sugar.
• Light Corn Syrup – Using a bit of corn syrup in the caramel and ganache gives them a glossy, silky smooth consistency. However, it can be omitted from both recipes if needed.
• Dark Chocolate – I love using dark chocolate (60-65% cocoa) to make the ganache topping. However, if you want to use milk chocolate to make the ganache, use 1/3 cup (80g) of heavy cream and 1 1/3 cups (240g) of milk chocolate.

Making This Millionaire Cake in Advance & Storage Tips

This cake can be stored at room temperature for up to 2 days, or in the fridge for up to a week. Store the cake in an airtight container or cover the pan tightly with plastic wrap and foil to keep it fresh.

You can also freeze this cake for up to 3 months! After it’s baked and cooled, remove it from the pan then freeze the entire cake until it’s firm to the touch (about 1 hour). Then wrap the cake in a couple of layers of plastic wrap and then foil.

When you’re ready to enjoy the frozen cake, place it in the fridge overnight, then unwrap it and enjoy it the following day. Wait to add the caramel and ganache topping until it’s thawed.

How To Make the Best Millionaire Cake

• Be sure the ingredients are at room temperature. It helps them mix together better.
• Properly measure your flour! I like to use a scale, but the fluff and level method works great too.
• Bake this cake in a metal pan, not a glass pan! Glass gets hotter than metal pans. If you have to bake these in a glass pan, bake them at 325 F.
• Cool the cake fully before cutting into it. It will make it much easier to get clean slices.
• Use a warm, sharp knife to get clean slices. Fill a tall cup with hot water and dip a sharp knife into it. Dry the knife fully, then make a slice. Repeat with each cut and wipe the blade clean after each cut.

Let Me Know What You Think!

If you make this millionaire cake, I’d love to hear what you think of it! Please leave a rating and comment below.

Don’t forget to tag me @chelsweets and #chelsweets if you share on social media! I love seeing your delicious creations.

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