Coffee Caramel Cake with Buttermilk

Quick Look at the Cake

This recipe uses a specific timing flow. You bake the sponges first, then make the caramel while they cool, and finish with the frosting. This prevents the caramel from being too runny when you assemble.

The cake stays moist thanks to the buttermilk, which keeps the sponge from drying out during the 35 minute bake.

The Building Blocks

Ingredient Breakdown

Ingredients and Substitutions

For the Coffee Sponge

• 2 cups (250g) all-purpose flour
• 1½ cups (300g) granulated sugar
• 1 cup (227g) unsalted butter, softened
• 3 large eggs
• 1 cup (240ml) buttermilk Why this? The acidity creates a more tender crumb
• 2 tbsp (12g) instant espresso powder
• 1 tbsp (12g) baking powder
• ½ tsp (3g) salt
• 1 tsp (5ml) vanilla extract

For the Coffee Caramel Cake Filling

• 1 cup (200g) packed light brown sugar
• ½ cup (115g) unsalted butter
• ½ cup (120ml) heavy cream, warmed Why this? Stops the caramel from seizing
• ½ tsp (3g) sea salt
• 1 tsp (5ml) vanilla extract

For the Espresso Buttercream

• 1 cup (227g) unsalted butter, softened
• 3 cups (360g) powdered sugar
• 2 tbsp (10g) instant espresso powder
• 3 tbsp (45ml) heavy cream
• 1 tsp (5ml) vanilla extract

Tools You'll Need

Prepare two 9-inch round cake pans and line the bottoms with parchment paper. An electric mixer is best for the creaming and whipping.

For the caramel, use a heavy-bottomed saucepan. Thin pans often create hot spots that can burn the sugar in seconds.

Step-by-step Instructions

Preparing the Coffee Sponge

1. Preheat the oven to 350°F (180°C). Grease two 9 inch round cake pans and line the bottoms with parchment paper.
2. Cream 1 cup (227g) softened butter and 1½ cups (300g) granulated sugar on medium-high speed until pale and fluffy.
3. Mix in 3 large eggs individually, then add 1 tsp (5ml) vanilla extract.
4. In a separate bowl, whisk together 2 cups (250g) all-purpose flour, 1 tbsp (12g) baking powder, ½ tsp (3g) salt, and 2 tbsp (12g) instant espresso powder.
5. Alternately add the dry ingredients and 1 cup (240ml) buttermilk to the butter mixture, starting and ending with the flour, until just combined. Note: Overmixing here makes the cake tough.
6. Split the batter between the two pans and bake for 30–35 minutes, until a tester inserted into the middle comes out clean.

Crafting the Golden Caramel

7. Over medium heat, melt ½ cup (115g) unsalted butter and 1 cup (200g) light brown sugar in a saucepan, stirring constantly until the sugar is dissolved.
8. Raise the heat slightly and bring to a gentle boil for 2-3 minutes without stirring until the color deepens to a rich amber.
9. Slowly whisk in ½ cup (120ml) warmed heavy cream and simmer for another 2 minutes until the sauce thickens.
10. Remove from heat, stir in ½ tsp (3g) sea salt and 1 tsp (5ml) vanilla, and let the caramel cool completely.

Whipping the Espresso Frosting

11. Beat 1 cup (227g) softened butter until smooth and creamy.
12. Sift in 3 cups (360g) powdered sugar and 2 tbsp (10g) instant espresso powder, mixing on low speed until incorporated.
13. Add 3 tbsp (45ml) heavy cream and 1 tsp (5ml) vanilla, then whip on high for 2-3 minutes until airy and stiff peaks form.

Assembling the Cake

14. Level the cooled cake layers with a serrated knife.
15. Place the first layer on a plate and pipe a ring of espresso buttercream around the top edge. Note: This prevents the caramel from leaking out the sides.
16. Fill the center of the buttercream ring with a generous layer of the cooled caramel sauce.
17. Place the second cake layer on top and frost the entire cake with the remaining espresso buttercream.
18. Drizzle any leftover caramel over the top of the cake for the finish.

Why the Coffee Stays Bold

• Double Espresso Hit: Adding espresso powder to both the sponge and the frosting ensures the coffee flavor doesn't disappear under the heavy sugar and butter.
• Buttermilk Acidity: The acid in the buttermilk breaks down gluten proteins, which creates a tender crumb that absorbs the coffee flavor better.
• The Frosting Dam: Piping a ring of buttercream around the edge holds the liquid caramel in place, so the layers stay separate.

Troubleshooting Guide

Fixing Grainy Caramel

Grainy caramel happens when sugar crystals don't fully melt. This usually comes from stirring too much during the boil or using a pan that isn't heavy enough to hold heat evenly.

Preventing Sunken Centers

If the cake sinks, it's often due to overmixing the batter or taking it out before the structure sets. Make sure your toothpick comes out completely clean before removing the pans.

Smoothing Lumpy Buttercream

Lumps occur if the butter was too cold or if the powdered sugar wasn't sifted. If this happens, whip the frosting on high for an extra minute to smooth out the texture.

Storing Leftovers

Store the dessert in a sealed container in the refrigerator for up to 5 days. The buttercream ensures it stays moist. Since the frosting's butter hardens when chilled, allow a slice to rest at room temperature for 30 minutes before serving.

For longer storage, wrap single portions in plastic film and then foil to freeze for up to 3 months. Thaw the slices in the fridge overnight. Avoid using a microwave to warm the cake, as this will melt the buttercream and make the sponge rubbery.

To prevent waste, use remaining caramel sauce as a dip for sliced pears or apples.

Make It Your Own

If you want a Salted Caramel Mocha Cake, fold ½ cup of mini chocolate chips into the batter just before baking. The chocolate complements the coffee and adds a different texture to the bite.

For a nuttier profile, add a tablespoon of espresso-flavored hazelnut spread to the buttercream. This gives it a flavor similar to a cafe latte.

If you enjoy a lighter caramel, you can use a caramel sauce that uses a higher ratio of cream to sugar. For those who prefer a different base, you can look at a birthday cake recipe for ideas on how to get an even more buttery sponge.

Serving Suggestions

Serve each slice of your Coffee Caramel Cake with a dollop of unsweetened whipped cream. The lightness of the cream cuts through the richness of the espresso and caramel.

Since this cake is quite sweet, it pairs best with a drink that has some bitterness. A shot of espresso or a glass of cold almond milk works well. For a more casual vibe, serve it alongside a bowl of fresh raspberries to add a tart contrast to the deep coffee notes.