In a world filled with towering, multi-layered cakes piled high with fluffy frosting, there is something profoundly elegant and satisfying about a dessert that shines with pure, unadorned simplicity. Meet the French Butter Cake, or as it’s known in its native Brittany, the Gâteau Breton. This is not your typical light and airy cake. It is something far more interesting: a dense, incredibly rich, and impossibly tender cake with a flavor that is unapologetically, luxuriously buttery.

Imagine the most decadent shortbread cookie you’ve ever had, transformed into a magnificent, golden, sliceable cake. It has a moist, slightly crumbly texture that melts in your mouth, and a beautiful, caramelized crust marked with a traditional crosshatch pattern. This is a cake that doesn’t need bells and whistles. It’s a testament to the French culinary philosophy that a few high-quality ingredients, treated with care, can create something truly extraordinary. It’s the perfect sophisticated treat to enjoy with your afternoon coffee or as a simple, stunning end to a meal.

Why I Love This Recipe

What captivates me about the Gâteau Breton is its bold confidence. It’s a cake built almost entirely on one ingredient: butter. And not just any butter—good, high-quality, preferably salted butter. The flavor is deep, nutty, and complex in a way that is simply unforgettable. The texture is another reason for my obsession. It’s firm enough to slice cleanly, yet it dissolves on the tongue into a state of pure, buttery bliss.

Making this cake feels like connecting with a timeless piece of baking history. It’s rustic and refined all at once. The process is straightforward, with no complicated techniques, yet the result is a dessert that feels incredibly special. It’s the kind of recipe that, once you make it, becomes a permanent part of your baking repertoire.

Ingredients

The ingredient list is deceptively short, which means the quality of each one is paramount.

• 1 cup plus 2 tablespoons (250g) High-Quality Salted Butter, softened to room temperature
• 1 1/4 cups (250g) Granulated Sugar
• 5 large Egg Yolks, at room temperature, divided
• 1 tsp Pure Vanilla Extract or 1 tbsp Dark Rum (optional)
• 2 cups (250g) All-Purpose Flour
• 1 ½ tsp Baking Powder
• Pinch of fine sea salt (ONLY if using unsalted butter)

Swaps and Notes:

• The Butter: This is the heart and soul of the cake. Traditionally, this cake is made with French salted butter from Brittany, which has a unique flavor and high-fat content. If you can find a good quality European-style salted butter, use it! If you only have unsalted butter, add a generous pinch of fine sea salt to the dough with the flour. Do not substitute with margarine or shortening.
• The Egg Yolks: This recipe uses only the yolks, which contributes to the cake’s rich color and tender, dense crumb. Save the egg whites for an omelet or to make meringues! You will need 4 yolks for the batter and 1 for the egg wash on top.
• The Flavoring: While delicious on its own, a splash of good vanilla extract or dark rum adds a lovely dimension that complements the buttery flavor. This is optional but highly recommended.

Step-by-Step Instructions

1. Prepare the Pan: Preheat your oven to 350°F (175°C). Grease and flour a 9-inch round cake pan or springform pan.
2. Cream Butter and Sugar: In the bowl of a stand mixer fitted with the paddle attachment, or in a large bowl with a hand mixer, beat the softened salted butter and sugar together on medium-high speed for 3-5 minutes. The mixture should become light, pale, and fluffy.
3. Add the Yolks: Add 4 of the egg yolks, one at a time, beating well after each addition. Scrape down the sides of the bowl as needed. Beat in the vanilla extract or rum, if using.
4. Combine Dry Ingredients: In a separate medium bowl, whisk together the all-purpose flour and baking powder (and the pinch of salt if you used unsalted butter).
5. Mix the Dough: Add the dry ingredients to the butter mixture all at once. Mix on low speed until the flour is just incorporated. The dough will be very thick, soft, and sticky, almost like a thick cookie dough. Do not overmix.
6. Press into Pan: Scrape the dough into your prepared cake pan. Because it’s so thick, you’ll need to use a spatula or your floured fingertips to press it into an even layer.
7. Create the Signature Top: In a small bowl, whisk the remaining 1 egg yolk with a teaspoon of water. Use a pastry brush to brush this egg wash evenly over the top of the cake.
8. Score the Pattern: Use the tines of a fork to gently drag across the top of the cake, first in one direction and then in the opposite, to create a classic diamond or crosshatch pattern.
9. Bake: Bake for 35-40 minutes, or until the cake is a deep golden brown and a wooden skewer inserted into the center comes out with moist crumbs attached, but not wet batter.
10. Cool Completely: Let the cake cool in the pan on a wire rack for at least 15-20 minutes before attempting to remove it. It’s very delicate when warm. Let it cool completely to room temperature before slicing. The texture and flavor are best once it has fully set.

Tips for Success

1. Quality Ingredients are Non-Negotiable: With so few ingredients, there’s nowhere to hide. Use the best butter you can find. It will make all the difference.
2. Room Temperature is Key: Using softened butter and room temperature egg yolks is crucial for creating a smooth, emulsified batter, which leads to a better cake texture.
3. Don’t Overmix the Flour: Once you add the flour, mix only until you no longer see dry streaks. Overmixing develops gluten and will result in a tough cake.
4. Patience During Cooling: This cake is one of those magical baked goods that gets better as it sits. The cooling process allows the crumb to set and the buttery flavor to deepen. Resist the urge to slice it warm!

Serving Suggestions

This Gâteau Breton needs very little adornment. Serve thin slices at room temperature. It’s the perfect companion to a strong cup of black coffee or tea. In the summertime, a few fresh raspberries or strawberries alongside a slice provides a lovely, tart contrast to the cake’s richness.

Storage and Leftover Tips

• Storage: Thanks to its high butter content, this cake keeps exceptionally well. Store it in an airtight container at room temperature for up to 5 days. Its flavor will continue to develop, and it’s just as delicious on day three as it is on day one.

More Recipes You Will Love

If you enjoy classic, satisfying baked goods, you’ll surely love some of our other favorite cookie and dessert recipes:

• For an iconic treat, try These Copycat Neiman Marcus Chocolate Chip Cookies.
• When autumn rolls around, keep These Caramel Apple Pie Cookies in mind.
• For a bit of winter coziness, nothing beats These Hot Chocolate Cookie Cups.
• For a foolproof classic, you can’t go wrong with These Old-School No-Bake Cookies.
• And for a festive project, check out The Easter Cookies Everyone Will Be Talking About.

Final Thoughts

The French Butter Cake is a beautiful reminder that you don’t need a long list of ingredients to create something truly memorable. It’s a humble yet luxurious cake that is all about flavor and texture. I hope you’ll try your hand at this little slice of Brittany and fall in love with its simple, buttery charm just as I have.

Let me know what you think in the comments below!