Mounds Cake with Coconut Filling
- Time: 20 min active + 30 min baking + 2 hr chilling
- Flavor & Texture: Deep chocolate with a chewy, coconut-rich center
- Perfect for: Potlucks or chocolate lovers who want something more than a standard sheet cake
Making a Mounds Cake
The weight is the first thing that stands out. This isn't a fluffy sponge, but a moist, dense chocolate base designed to support a thick layer of coconut and ganache. It is a hearty, satisfying treat.
The objective is to replicate the exact contrast found in a Mounds bar: the bitterness of cocoa paired with sweet condensed milk and chewy coconut.
The method is simple: bake, poke, spread, and chill. You can't rush the chilling process, as this is when the layers merge into a single, cohesive slice.
How the Filling Sinks In
The Poke Method: Creating holes in the warm cake allows the condensed milk and coconut to soak into the sponge instead of just sitting on top.
Condensed Milk Binder: This creates a chewy, fudge-like texture that mimics a candy bar better than a traditional frosting would.
Base Method Comparison
| Method | Time | Texture | Best For |
|---|---|---|---|
| From Scratch | 50 min | Deep, cocoa-rich | Those who want a precise flavor balance |
| Cake Mix | 35 min | Lighter, sweeter | A fast weekday treat |
Ingredient Deep Dive
| Ingredient | What It Does | Best Swap |
|---|---|---|
| Buttermilk | Adds tang and tenderizes the crumb | Equal parts milk and lemon juice |
| Boiling Water | Blooms the cocoa for a darker flavor | Hot coffee to deepen the chocolate |
| Condensed Milk | Binds coconut into a thick paste | Coconut condensed milk (for a nuttier taste) |
| Cocoa Powder | Provides the core chocolate structure | Dutch processed for a smoother taste |
For the Chocolate Base
- 2 cups (250g) all-purpose flour
- 2 cups (400g) granulated sugar
- 3/4 cup (75g) unsweetened cocoa powder
- 2 tsp (10g) baking soda
- 1 tsp (5g) salt
- 1 cup (240ml) buttermilk Why this? The acid reacts with baking soda for lift
- 1/2 cup (115g) vegetable oil
- 2 large eggs
- 1 cup (240ml) boiling water Why this? It thins the batter and activates the cocoa
For the Coconut Filling
- 1 can (14 oz / 397g) sweetened condensed milk
- 3 cups (270g) shredded sweetened coconut
- 1 tsp (5g) vanilla extract
For the Glossy Chocolate Topping
- 1 cup (175g) semi-sweet chocolate chips
- 1/2 cup (120ml) heavy cream
- 2 tbsp (28g) unsalted butter, room temperature
Necessary Baking Tools
You'll need a 9x13 inch baking pan. A wooden skewer or a thin chopstick is essential for poking the holes. For the ganache, a heat-proof glass or metal bowl works best so the chocolate doesn't seize. A whisk and a medium mixing bowl handle the rest.
How to Make It
1. Baking the Foundation
Preheat your oven to 180°C (350°F) and thoroughly grease a 9x13 inch baking pan. In a large bowl, whisk together 250g all-purpose flour, 400g granulated sugar, 75g unsweetened cocoa powder, 10g baking soda, and 5g salt.
Incorporate 240ml buttermilk, 115g vegetable oil, and 2 large eggs into the dry ingredients. Beat on medium speed until the mixture is smooth, then stir in 240ml boiling water by hand. Note: the batter will be thin, which is expected.
Pour the batter into the pan and bake for 30-35 minutes until a cake tester pulled from the center reveals just a few moist crumbs.
2. Creating the Coconut Infusion
While the cake is still warm, use a wooden skewer to poke holes every inch across the surface. In a medium bowl, fold together 397g sweetened condensed milk, 270g shredded sweetened coconut, and 5g vanilla extract until a thick, creamy paste develops.
Spread the coconut mixture evenly over the warm cake, pressing it gently into the holes to ensure the Mounds cake is fully saturated.
3. The Finishing Glaze
Place 175g semi-sweet chocolate chips in a heat-proof bowl. Bring 120ml heavy cream to a simmer in a saucepan, then pour it over the chocolate chips.
Allow the chocolate and cream to rest for 5 minutes. Whisk in 28g room-temperature unsalted butter until the ganache has a silky texture and a mahogany colored sheen. Pour the ganache over the coconut layer, tilting the pan to coat the surface evenly.
Chill the cake in the refrigerator for at least 2 hours to set the layers before slicing into squares.
Fixing Your Mounds Cake
If the cake feels too dry, it usually happens because the flour was packed too tightly into the measuring cup. I prefer weighing ingredients in grams to avoid this. If the ganache looks grainy, the cream might have boiled too hard, which can separate the fats.
Fixing a Dry Sponge
Overbaking by even five minutes can dry out the base. If this happens, ensure you poke the holes while the cake is very warm so the filling can really penetrate.
Handling Broken Ganache
If the chocolate doesn't melt smoothly, gently stir in a teaspoon of warm cream or butter. This usually brings the emulsion back together.
Managing a Runny Filling
If the coconut layer feels too loose, you might have used a brand of condensed milk with higher moisture. Adding another handful of shredded coconut can thicken it up.
| Problem | Fix |
|---|---|
| Dry cake base | Poke holes while very warm; add more filling |
| Grainy ganache | Stir in a small amount of warm cream |
| Filling too soft | Mix in extra shredded coconut |
Easy Swaps and Add-Ins
For a different flavor profile, consider a Dark Chocolate Espresso variation. Stir 1 tablespoon of instant espresso powder into the dry ingredients; the coffee's bold notes balance out the sweetness of the condensed milk.
To save time, you can use a Mounds cake recipe that utilizes a cake mix as the base. Simply follow the package directions, but keep the poke hole and filling steps exactly the same. For an even quicker treat, try these Chocolate Cake Mix Cookies.
I also recommend a Toasted Coconut Twist. Brown the shredded coconut in a dry pan over medium heat for 3-5 minutes until golden before stirring it into the condensed milk. This provides the center with a deeper, nuttier flavor.
Storing Leftovers
Due to the condensed milk in the filling, this Mounds cake needs to be refrigerated. Store it in an airtight container or cover it with plastic wrap for up to 5 days.
This cake also freezes beautifully. First, cut it into squares and wrap each piece individually in parchment paper. Store them in a freezer bag for up to 3 months. To serve, let a slice defrost in the refrigerator overnight.
It is delicious chilled, but leaving it at room temperature for 20 minutes gives the chocolate base a more fudgy texture.
Perfect Complements
Since this is a very rich dessert, a tart accompaniment helps balance the sugar. Fresh raspberries or a dollop of unsweetened whipped cream are my go to choices. A glass of cold milk is the classic pairing, but a strong black coffee also works well to offset the coconut sweetness.
Recipe FAQs
How to make the Mounds cake filling?
Fold together sweetened condensed milk, shredded sweetened coconut, and vanilla extract until a thick paste forms.
Tip: Press the mixture gently into the holes of the warm cake to ensure it is fully saturated.
Can I use sweetened condensed milk in this cake?
Yes, it is the primary ingredient used to create the creamy coconut layer.
Tip: Try using this same ingredient for a rich dessert cake.
Is this a chocolate Mounds cake?
Yes, the recipe uses a moist cocoa-based cake topped with coconut and chocolate ganache.
Tip: Allow a chilled slice to sit at room temperature for 20 minutes to make the base feel fudgier.
Where should I store the leftovers?
Keep the cake covered in the refrigerator for up to 5 days.
Tip: Wrap individual squares in parchment paper and freeze them in a bag for up to 3 months.
Mounds Cake with Coconut Filling