Millionaire Cake

4.94 from 29 ratings

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!

Prep Time30

Cook Time38

Additional Time30

Total Time1 38

Course: Cakes

Cuisine: American

Servings: 16

Calories: 336kcal

Author: Chelsey White

Ingredients

Caramel Topping

2/3 cup (half a 14 oz. can) sweetened condensed milk 200g
1/4 cup unsalted butter, cut into chunks 56g
1/4 cup packed light brown sugar 50g
2 Tbsp light corn syrup 30g
1 tsp vanilla extract or vanilla bean paste 4g
1/2 tsp fine salt 3g

Shortbread Crust

3/4 cup unsalted butter, room temperature 170g
1 1/2 cups all-purpose flour 190g
1/3 cup powdered sugar 40g
1/4 tsp fine salt 1g

Brown Butter Cake Layer

1 cup cake flour 125g
1 cup granulated sugar 200g
3/4 tsp baking powder 3g
1/2 tsp fine salt 3g
6 Tbsp unsalted browned butter, room temperature 85g
1/3 cup carton egg whites or 3 large egg whites, room temperature 80g
1/2 cup buttermilk, room temperature 120g
1 Tbsp vegetable or canola oil 14g
1 tsp vanilla extract or vanilla bean paste 4g

Chocolate Ganache Topping

3/4 cup heavy whipping cream, room temperature 180g
1 cup + 1 Tbsp dark (60-65% cocoa) chocolate chips 180g
2 Tbsp unsalted butter, room temperature 30g
1 Tbsp light corn syrup - optional 20g
1/4 tsp fine salt 2g

Garnish - Optional

flakey sea salt - garnish

Equipment / Tools Needed

Instructions

Caramel Topping

Make the caramel filling first so that it can thicken up before we spread it to top the cake.
Heat 2/3 cup sweetened condensed milk, 1/4 cup butter, 1/4 cup packed brown sugar, and 2 Tbsp 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 allow the caramel to simmer.
Continue to stir frequently until the mixture thickens and becomes a medium caramel color (about 5 minutes). If the butter doesn't get fully incorporated into the caramel (this can happen if the caramel gets cooked at slightly too high of a temperature), don't worry! You can gradually stir the melted butter into the caramel as it cools and it will come together once it reaches room temperature.
Remove the caramel from the heat and stir in 1 tsp vanilla extract and 1/2 tsp fine 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. If you refrigerate the caramel, heat it in the microwave in short 10-second intervals and stir between until it reaches room temperature and is a more workable consistency.

Shortbread Crust

Next, work on the shortbread crust. Preheat the oven to 350 F / 175 C. Line an 8x8-inch square, metal baking pan with parchment paper. Set aside
Use a pastry cutter or electric mixer to combine 3/4 cup butter, 1 1/2 cups flour, 1/3 cup powdered sugar, and 1/4 tsp fine salt.
Next, press the mixture into an even layer in the prepared pan with your fingers. Prick the crust thoroughly with a fork, then bake for 20-24 minutes, or until the edges are just starting to brown.
Place the pan on a wire rack to cool. Keep the oven on at 350 F / 175 C for the cake that we'll bake next!

Brown Butter Cake Layer

While the crust cools, make the vanilla cake batter.
Mix together 1 cup cake flour, 1 cup granulated sugar, 3/4 tsp baking powder, and 1/2 tsp fine salt in a large bowl. Use a stand mixer with a paddle attachment or hand mixer to mix on a low speed until combined.
Mix 6 Tbsp unsalted brown butter slowly into the dry mix, on a medium-low speed. Continue to mix until no large chunks of butter remain, and the mixture becomes crumbly.
Pour in 1/3 cup pasteurized egg whites from a carton or 3 large egg whites and mix on low until just incorporated and the batter looks wet.
Mix in 1/2 cup of buttermilk, 1 Tbsp of vegetable oil, and 1 tsp vanilla extract on a low speed. Scrape the sides and bottom of the bowl as needed with a rubber spatula, then beat on a medium speed for 30 seconds to make sure everything is properly mixed together. This also helps lighten the texture of the cake a bit.
Pour the batter over the cooled shortbread crust, then bake for 36-40 minutes, or until a toothpick comes out with a few moist crumbs. Let the cake cool fully in the pan.
If you're short on time, you can pop the cake (pan and all) into the freezer for 30 minutes to accelerate the cooling process. Once the cake is fully cooled, gently lift the cake out of the pan using the overhanging parchment paper.

Chocolate Ganache Topping

Then we tackle the chocolate ganache! I like to make it as the cake bakes and cools because it needs time to cool and thicken.
Heat 3/4 cup of heavy cream in a heatproof bowl in the microwave for 45 seconds, until it's just beginning to bubble.
Gently pour 1 cup + 1 Tbsp of dark chocolate chips into the heavy cream. Make sure the chips are fully covered with cream. Let the mixture sit for 1 minute. 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.
Stir slowly until the cream and chocolate combine 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.
Mix in 2 Tbsp of room temperature unsalted butter, 1 Tbsp corn syrup, and 1/4 tsp fine salt until combined.
Cover with plastic wrap to prevent the ganache from forming a skin, then set aside to cool to room temperature. If you're in a rush, pour the ganache into a wide, shallow container to help it cool down faster. If you need to make this in advance, it can be covered and stored in the fridge for up to a month.

Decorating This Millionaire Cake

Once the cake layer has fully cooled, scoop the room-temperature caramel on top of the cake and spread it into an even layer.
Then spread the room-temperature chocolate ganache on top of the caramel.
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 up to 2 days, or in the fridge for up to a week in an airtight container.

Video

Notes

Ingredient Swaps & Substitutions

For a detailed list of ingredient swaps and substitutions that can be made in each component of this recipe, please refer to the "swaps and substitutions" section above.

Making This Millionaire Cake in Advance

This cake can be stored at room temperature for 2 days, or in the fridge for up to a week. Store slices 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 they're baked and cooled, remove them from the pan then freeze the entire sheet of 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.

Doubling this Recipe

If you want to double this recipe, go for it! Simply double the ingredients and follow the directions in the recipe card above.

Bake a double batch in a 9 x 13-inch pan at 350 F / 175 C for 40-50 minutes.

How to Make the Best Millionaire Cake

Be sure the ingredients are at room temperature. It helps them mix together better.
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.
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.
If the butter doesn't get fully incorporated into the caramel (this can happen if the caramel gets cooked at slightly too high of a temperature), don't worry! You can gradually stir the butter into the caramel as it cools and it will come together once it reaches room temperature. It won't be quite as smooth as normal, but it will still taste great!
Chill 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 this with each cut, and wipe the blade clean after each cut.

Nutrition