Why is my caramel not thickening?

The most common reason is heat that's too low or inconsistent stirring. Make sure you're using medium-low heat and stirring constantly. The process should take about 20 minutes—if it's taking much longer, you can slightly increase the heat. Be patient; it will suddenly transform into that beautiful thick caramel.

Can I use unsalted butter instead?

Absolutely! If using unsalted butter, add ¼ teaspoon of salt to both the cookie base and the caramel filling to maintain that sweet-salt balance that makes these bars so addictive.

My chocolate layer cracked when cutting—how can I prevent this?

Let the bars sit at room temperature for about 15 minutes before cutting. The coconut oil in the chocolate helps prevent hardness, but if your refrigerator is very cold, the chocolate might become too firm. Using a hot knife (heated under hot water and dried) also helps create clean cuts.

Can I double this recipe?

Yes! For a crowd, double all ingredients and use two 9x13 pans rather than one larger pan. This maintains the perfect ratio of layers and ensures even baking of the shortbread base.

Millionaire Bars Recipe

Name: Millionaire Bars Recipe
Prep time: 20 min
Cook time: 20 min
Total time: 40 min
Cuisine: American
Ingredients: 1 cup salted butter, softened; 1/2 cup granulated sugar; 2 Tbsp brown sugar; 2 1/2 cups all-purpose flour; 1/2 cup salted butter; 1/2 cup brown sugar; 1 (300 ml/140 oz) can sweetened condensed milk; 1 tsp vanilla extract; 2 cups chocolate chips; 1 Tbsp coconut oil

This indulgent three-layer treat combines a buttery shortbread base, creamy caramel middle, and rich chocolate topping for an irresistible dessert experience. Millionaire Bars (also known as caramel shortbread) are surprisingly simple to make despite their fancy appearance, making them perfect for impressing guests or treating yourself after a long day. The contrasting textures and complementary flavors create a dessert that truly lives up to its wealthy name!

Why You’ll Love This Recipe

Triple-Layer Delight: Three distinct layers that work together beautifully—crisp cookie base, smooth caramel center, and snappy chocolate top.
Make-Ahead Friendly: These bars actually improve after chilling, making them perfect for preparing a day before your event.
Customizable: Easy to adapt with different chocolate types or add-ins to make them uniquely yours.
Crowd-Pleaser: I’ve never met anyone who can resist these bars—they disappear quickly at gatherings!

Ingredients You’ll Need

Cookie Layer

Salted butter: Creates a rich, tender shortbread base and adds a subtle savory note that balances the sweetness.
Granulated sugar: Provides the perfect level of sweetness without overwhelming the other flavors.
Brown sugar: Adds depth of flavor and a hint of molasses that complements the caramel layer.
All-purpose flour: The structure of our shortbread layer—no need for anything fancy here.

Filling

Salted butter: Forms the base of the caramel and adds richness.
Brown sugar: Transforms into that magical caramel flavor when cooked with the other ingredients.
Sweetened condensed milk: The secret to achieving that perfect creamy, thick caramel without needing candy-making skills.
Vanilla extract: Adds warmth and depth to the caramel layer—don’t skip this!

Chocolate Topping

Chocolate chips: Use semi-sweet for classic flavor, but dark or milk chocolate work wonderfully too.
Coconut oil: Helps the chocolate layer set with the perfect texture—not too hard to cut, but firm enough to hold its shape.

Note: You’ll find the complete list of ingredients, along with their exact measurements, in the printable recipe card at the bottom of this post.

Variations

Chocolate Options: Try dark chocolate for a less sweet version, or swirl white and dark chocolate on top for an elegant look.
Salt Lovers: Sprinkle flaky sea salt on the chocolate layer before it sets for a salted caramel experience.
Nutty Twist: Add a layer of chopped toasted nuts (pecans or almonds work beautifully) between the caramel and chocolate.
Flavor Boosters: Add a teaspoon of espresso powder to the chocolate layer, or mix in orange zest with the shortbread base.

How to Make Millionaire Bars

Step 1: Prepare the Cookie Base

Preheat your oven to 350°F. Line a 9×13 inch baking pan with aluminum foil, leaving some overhang for easy removal later. Melt the butter, then mix in both sugars and flour until a dough forms. Press this mixture evenly into your prepared pan. Bake for 20-25 minutes until the edges are just turning golden brown.

Step 2: Create the Caramel Layer

While the cookie base bakes, combine butter, brown sugar, and sweetened condensed milk in a medium saucepan over low heat. This is where patience pays off! Stir constantly for about 20 minutes as the mixture thickens and transforms into a beautiful caramel color. Once it’s ready, remove from heat and stir in the vanilla extract. Pour this caramel goodness over the baked cookie layer and allow it to cool completely.

Step 3: Add the Chocolate Topping

In a microwave-safe bowl, combine chocolate chips and coconut oil. Microwave in 30-second intervals, stirring between each until perfectly smooth. Pour this over the cooled caramel layer, spreading it into an even layer.

Step 4: Chill and Serve

Place the pan in the refrigerator until the chocolate has set, typically 1-2 hours. Once set, use the foil overhang to lift the entire dessert out of the pan. Cut into squares or rectangles with a sharp knife. I find wiping the knife between cuts gives you the cleanest edges.

Pro Tips for Making the Recipe

Room Temperature Ingredients: Let the butter soften properly for the cookie layer—it makes mixing much easier.
Watch That Caramel: Don’t rush the caramel process. Low and slow is the key to perfect texture without burning.
Clean-Cut Technique: For picture-perfect bars, chill thoroughly, then dip your knife in hot water and wipe dry between cuts.
Pan Preparation: The foil lining isn’t just convenient—it’s crucial for easy removal without breaking your bars.

How to Serve

Perfect Pairings

These rich bars are wonderful alongside a hot cup of coffee or cold glass of milk to balance their sweetness. For an extra-special dessert presentation, serve slightly chilled with a small scoop of vanilla ice cream on the side.

Presentation Ideas

Arrange on a tiered serving plate for gatherings, or stack in a clear glass jar as a beautiful homemade gift. For holidays, consider cutting into smaller bites and placing in mini cupcake liners for easy finger-food desserts.

Make Ahead and Storage

Storing Leftovers

Store these bars in an airtight container at room temperature for up to 3 days, or refrigerate for up to a week. The flavors actually develop nicely after the first day!

Freezing

These bars freeze beautifully! Layer them between pieces of parchment paper in an airtight container and freeze for up to 3 months.

Reheating

No need to reheat—simply thaw at room temperature for about 30 minutes before serving. If you prefer the caramel to be slightly softer, 10 seconds in the microwave will do the trick.

FAQs

Why is my caramel not thickening?

The most common reason is heat that’s too low or inconsistent stirring. Make sure you’re using medium-low heat and stirring constantly. The process should take about 20 minutes—if it’s taking much longer, you can slightly increase the heat. Be patient; it will suddenly transform into that beautiful thick caramel.
Can I use unsalted butter instead?

Absolutely! If using unsalted butter, add ¼ teaspoon of salt to both the cookie base and the caramel filling to maintain that sweet-salt balance that makes these bars so addictive.
My chocolate layer cracked when cutting—how can I prevent this?

Let the bars sit at room temperature for about 15 minutes before cutting. The coconut oil in the chocolate helps prevent hardness, but if your refrigerator is very cold, the chocolate might become too firm. Using a hot knife (heated under hot water and dried) also helps create clean cuts.
Can I double this recipe?

Yes! For a crowd, double all ingredients and use two 9×13 pans rather than one larger pan. This maintains the perfect ratio of layers and ensures even baking of the shortbread base.

Final Thoughts

There’s something magical about these Millionaire Bars that keeps everyone coming back for more. The combination of buttery shortbread, creamy caramel, and smooth chocolate creates a treat that feels both homemade and fancy at the same time. Don’t be surprised if these become your new signature dessert—they’ve certainly earned that status in my kitchen! Give them a try this weekend and watch how quickly they disappear.

Why You’ll Love This Recipe