Moist Reeses Chocolate Cake with Buttermilk

Moist Reeses Chocolate Cake

The fragrance blooms the instant boiling water touches the cocoa powder. It's a rich, roasted scent that permeates the kitchen, making you feel as if you've stepped into a chocolate factory.

I previously struggled with using only melted butter, which seemed logical but frequently left me with a cake as dense as a brick by the next morning.

Discovering the mix of oil and buttermilk was a game changer. The difference is striking: the crumb stays remarkably moist, and the saltiness of the peanut butter stands out clearly against the sugar.

This Reese's-inspired chocolate cake is a study in balance. Between the dark mahogany layers and a frosting that mirrors the heart of the candy bar, it’s the sort of dessert that prompts guests to ask for the recipe before they've even finished their first slice.

Why Most Recipes Fail

A lot of chocolate cakes end up dry because they rely on a standard creaming method. That works for vanilla, but for chocolate, it often traps too much air and lets moisture escape.

Oil and Buttermilk: Using oil instead of butter in the sponge keeps it tender. Since oil stays liquid at room temperature, the Moist Reeses Chocolate Cake feels softer on the tongue. If you love this style, you might also like my Butter Cake with Buttermilk recipe for a different twist.

The Boiling Water: This isn't just for thinning the batter. The heat "blooms" the cocoa, releasing oils and flavors that you just don't get with cold liquids. It transforms the chocolate from a generic sweetness to something intense and dark.

Simple Recipe Specs

Here are the details. This is a rich dessert, so it's best served in thin slices rather than large wedges.

While the prep is fast, the chilling process is essential. If you skip the hour in the fridge, the peanut butter frosting could slide right off the cake as you cut it. Take my word for it I've had an entire layer slip onto a plate in front of guests.

The total time is 1 hours 30 mins, but most of that is just waiting for the baking to finish and the frosting to set.

Everything You'll Need

All measurements are provided in grams and milliliters. Using a digital scale ensures accuracy, particularly for the flour and powdered sugar.

For the Chocolate Sponge:

• 2 cups (250g) all-purpose flourThe reason: Provides the ideal protein balance for a soft yet sturdy texture
• 2 cups (400g) granulated sugar
• 3/4 cup (65g) unsweetened cocoa powderThe reason: Natural cocoa creates a richer, deeper hue
• 2 tsp (10g) baking soda
• 1 tsp (5g) baking powder
• 1 tsp (6g) salt
• 1 cup (240ml) room temperature buttermilkThe reason: Its acidity activates the baking soda for a superior lift
• 1/2 cup (120ml) vegetable oil
• 2 large eggs, room temperature
• 2 tsp (10ml) vanilla extract
• 1 cup (240ml) boiling water

For the Peanut Butter Frosting & Topping:

• 1 cup (225g) unsalted butter, softened
• 1 cup (250g) creamy peanut butterThe reason: Smooth versions incorporate more seamlessly into the frosting
• 4 cups (500g) powdered sugar
• 3 tbsp (45ml) heavy cream
• 1 tsp (5ml) vanilla extract
• 1/4 tsp (1.5g) salt
• 1 cup (150g) Reese's Peanut Butter Cups, chopped

You can substitute the buttermilk with milk and a teaspoon of lemon juice. Any neutral oil, such as canola, is a good replacement for vegetable oil. If heavy cream isn't available, use whole milk, though the frosting will be slightly less decadent.

Tools for the Job

No specialized equipment is required. While a stand mixer is a helpful tool, a simple hand mixer and a few bowls are all you really need.

• Two 9 inch round cake pans
• Parchment paper
• Large mixing bowl
• Whisk and rubber spatula
• Wire cooling rack
• Offset spatula for frosting

A quick note: ensure your pans are exactly 9 inches. If you opt for 8 inch pans, the cakes will be taller, meaning you'll need to increase the bake time by roughly 5-8 minutes.

Putting It All Together

Let's crack on. The key here is the order of operations. We want the dry ingredients perfectly mixed before the wet ones hit.

Phase 1: Preparing the Base

1. Preheat oven to 350°F (175°C). Grease two 9 inch cake pans and line the bottoms with parchment paper. Note: This prevents the cake from sticking to the bottom
2. Whisk together flour, sugar, cocoa powder, baking soda, baking powder, and salt in a large bowl.
3. Add buttermilk, vegetable oil, eggs, and vanilla extract. Beat on medium speed for 2 minutes until the batter is smooth and glossy.
4. Stir in the boiling water by hand. Note: The batter will look very thin, which is correct for a Moist Reeses Chocolate Cake homemade

Phase 2: The Bake and Cool

5. Divide the batter evenly between the two prepared cake pans.
6. Bake for 30 minutes until a toothpick comes out clean. You'll smell a strong, sweet cocoa aroma when they're nearly done.
7. Let the cakes cool in the pans for 10 minutes, then move them to a wire rack. Note: They must be completely cold before frosting or the butter will melt

Phase 3: Frosting and Assembly

8. Beat softened butter and peanut butter together. Gradually add powdered sugar, heavy cream, vanilla, and salt until the mixture is velvety and spreadable.
9. Spread a thick layer of frosting on the first cake, place the second cake on top, and cover the whole thing in the remaining frosting.
10. Press the chopped Reese's Peanut Butter Cups into the top and sides.
11. Chill the cake for 1 hour in the fridge. Note: This sets the peanut butter fat for clean slices

Solving Common Cake Issues

Things don't always go perfectly. Often, the culprit is simply the temperature or the timing.

If the Cake Sinks in the Middle

Opening the oven prematurely or using expired baking soda can cause the center to dip. The structure fails before it has a chance to set. If this occurs, simply mask the hole with additional frosting.

If the Frosting is Too Runny

This is typically caused by butter that is too soft or adding an excess of cream. Place the frosting bowl in the refrigerator for 10 minutes, then whip it again.

If the Cake Sticks to the Pan

This is why parchment paper is highly recommended. If you forgot to use it, carefully slide a thin knife around the edge of the pan before flipping it over.

Plate it Up

When you're ready to serve the Moist Reeses Chocolate Cake, take it out of the fridge about 20 minutes before slicing. This lets the butter soften slightly so the flavor is more pronounced.

For the cleanest cuts, use a sharp knife dipped in hot water and wiped clean between every slice. This stops the peanut butter frosting from dragging down into the chocolate layers.

If you want to be a bit fancy, serve each slice with a small dollop of whipped cream or a few fresh raspberries. The tartness of the berries cuts through the richness of the peanut butter.

Keeping It Fresh

Since this cake has a high fat content from the oil and peanut butter, it stays moist longer than most.

Store the cake in an airtight container. In the fridge, it lasts about 5 days. If you want to keep it longer, you can wrap individual slices in plastic wrap and freeze them for up to 2 months. To eat, just let a slice thaw in the fridge overnight.

For zero waste, if you have leftover frosting, don't toss it. It's basically a peanut butter dip. Use it for apple slices or dip some pretzels into it for a quick snack.

Twist the Flavor

Once you've got the base down, you can play around with the toppings and fillings.

• Salted Caramel: Drizzle salted caramel sauce between the layers before adding the frosting.
• Extra Chocolate: Use a dark chocolate ganache instead of the peanut butter frosting for a more intense profile. For more ideas on large scale treats, check out this Layer Cake for 16 recipe.
• Crunchy Version: Use crunchy peanut butter in the frosting for a bit of texture.

Quick Decision Guide:

• More salt? → Add 1/2 tsp flaky sea salt on top
• Lighter texture? → Use 1 cup of cake flour instead of AP
• More "candy" taste? → Fold chopped Reese's into the batter before baking

Right then, that's the Moist Reeses Chocolate Cake. It's rich, it's salty, and it's exactly what you want when you have a serious chocolate craving. Just remember to let it chill, or you'll be eating a peanut butter puddle. Enjoy!