Mounds Bar Cake Recipe with Chocolate and Coconut

What to Expect from This Mounds Bar Cake

This Mounds-inspired sheet cake is built around the candy bar’s defining contrast: deep chocolate and sweet coconut, without nuts. The cake remains soft and sturdy enough to support a substantial coconut layer, while the ganache firms into a smooth finish that can be cut cleanly.

• The 9×13-inch format gives every serving a visible coconut center.
• Sweetened coconut and marshmallows create a cohesive, chewy filling rather than a loose coconut topping.
• The finished cake is richest when served in modest squares with coffee or unsweetened tea.

Why the Chocolate, Coconut and Marshmallow Layers Work

A boxed devil’s food mix is used here because it delivers a moist, sliceable crumb with very little preparation. Sweetened shredded coconut supplies both chew and sweetness, while the milk-marshmallow mixture binds the flakes into a layer that firms as it cools. Semisweet chocolate keeps the ganache from becoming overwhelmingly sweet alongside the cake and filling.

• Evaporated milk adds dairy solids and richness without the extra sugar of condensed milk.
• Marshmallows provide structure as they melt, helping the coconut layer hold together.
• A relatively chocolate-forward ganache sets more reliably than a thin glaze and remains tender enough to slice.

Ingredients

• 1 box devil’s food cake mix, 15.25-ounce box
• 3 large eggs
• 1/2 cup neutral vegetable oil
• 1 cup water
• 1 cup evaporated milk, divided
• 3/4 cup granulated sugar
• 4 tablespoons unsalted butter, divided
• 10 ounces miniature marshmallows
• 4 cups sweetened shredded coconut
• 1/2 teaspoon fine salt, divided
• 1 teaspoon vanilla extract
• 12 ounces semisweet chocolate, finely chopped
• 2/3 cup heavy cream

How to Assemble the Chocolate Coconut Cake

Temperature control is the central technique. The cake should be warm enough for the filling to settle onto its surface, but not so hot that it becomes gummy. Spread the coconut mixture as soon as it reaches a thick, workable consistency; waiting too long can make it seize in the saucepan.

• Stir the milk, sugar, butter and marshmallows frequently over moderate heat to prevent scorching.
• Spread the filling promptly and use a flexible spatula to reach the corners without tearing the cake.
• Cool the coconut layer completely before adding ganache so the chocolate remains distinct instead of melting into it.
• Let the ganache thicken before spreading; warm, fluid ganache can migrate into the coconut layer.

How to Tell When the Cake and Layers Are Ready

Chocolate cake can look moist even when the center is underbaked, so check the middle rather than relying on browned edges. The correct coconut filling is glossy and cohesive, with enough body to stay where it is spread. Once chilled, the cake should cut with slight resistance from the ganache and no sliding between layers.

• A few moist crumbs on a tester are acceptable; streaks of liquid batter are not.
• The cake center should spring back lightly when pressed.
• The coconut layer should not release liquid around its edges.
• If using an instant-read thermometer as a secondary check, a finished cake is commonly in the approximate 200 to 210°F range at the center.

For additional guidance on checking cake doneness by texture and tester results, see King Arthur Baking’s guide to telling when cake is done.

The Variables That Keep the Layers Stable

The cake’s thickness, the amount of liquid absorbed by the coconut, and the chocolate-to-cream balance all affect the final structure. Evaporation concentrates the filling while it cooks, and cooling allows the marshmallow mixture to set. In the ganache, the chocolate must provide enough cocoa solids and cocoa butter to bind the cream into a coating rather than a sauce.

• A smaller or deeper pan changes the distance heat must travel, so its bake time cannot be copied directly from the 9×13-inch version.
• Sweetened coconut is moister than unsweetened coconut; changing coconut types can alter both sweetness and filling consistency.
• More cream makes a softer ganache, while more chocolate makes a firmer one.
• Refrigeration improves slice stability, but a short room-temperature rest brings back a more tender crumb and softer chocolate texture.

Common Mounds Cake Problems and How to Fix Them

Most problems with this cake come from temperature or moisture rather than complicated technique. Watch the saucepan closely, allow the cake to cool at the specified stages, and judge the filling by its consistency before spreading.

• Runny filling: Cook the milk-marshmallow mixture a little longer before adding the coconut, or return the finished mixture briefly to low heat. Excess liquid or insufficient concentration is usually the cause.
• Scorched filling: Use medium-low heat and stir across the bottom and corners continuously. A burned mixture cannot be fully repaired, so discard it if it tastes bitter.
• Gummy cake top: The cake or filling was too hot during assembly. Let the cake cool until warm rather than steaming.
• Soft ganache: Cool it longer before spreading. If it remains loose after chilling, the cream-to-chocolate balance was too fluid for a firm topping.
• Cracked ganache: Let the cake stand briefly at room temperature and use a warm, dry knife. Cutting while the topping is very cold can make it fracture.
• Dry cake: Check the center early and remove the cake as soon as the tester shows moist crumbs. A smaller or darker pan may bake the edges faster.

Ingredient Substitutions for This Mounds Cake

The boxed cake base is the simplest route, but the filling and topping can be adjusted if needed. Substitutions change the dessert’s sweetness, richness or firmness, so they should be made with those tradeoffs in mind.

• For a from-scratch base, use a moist chocolate cake formula designed for a 9×13-inch pan and bake until the center is set; do not substitute an unusually delicate cake that cannot support the filling.
• Evaporated milk may be used in the same amount wherever regular milk is called for in a filling, producing a richer result. Sweetened condensed milk is not a direct swap because it contains substantial sugar and creates a denser, sweeter layer.
• Unsweetened shredded coconut can replace sweetened coconut, but the filling will be less sweet and potentially drier. Add sweetness and liquid only after assessing the mixture’s consistency.
• Milk chocolate can replace semisweet chocolate for a sweeter topping, but it generally needs less cream to achieve a comparable set.
• Avoid almond extract and nuts in the main recipe if the goal is a Mounds-style flavor rather than an Almond Joy variation.

Mounds Cake Variations That Still Work

The sheet cake is the most dependable format because it keeps the coconut layer level and eliminates stacking concerns. Other formats are possible, but they change the way the coconut is distributed and should not be expected to eat exactly like this version.

• For a poke cake, poke the baked cake and use a thinner condensed-milk or coconut mixture to infuse the crumb. The result will be softer and more integrated, not a distinct coconut center.
• For a round layer cake, divide the batter between prepared round pans and cool the coconut filling completely before stacking. Keep the filling layer modest to prevent sliding.
• A Bundt cake can include coconut in the batter and chocolate glaze, but it will not provide the same full, visible coconut layer.
• Toasted coconut is suitable as an optional garnish, but its browned, nutty flavor is less like the soft coconut profile of a classic Mounds bar.

How to Serve Chocolate Coconut Layer Cake

Refrigeration gives this rich cake its cleanest layers and most polished appearance. For the best balance between neat slices and tender texture, remove portions from the refrigerator 20 to 30 minutes before serving.

• Use a sharp knife warmed under hot water and wiped dry for smooth cuts through the chilled ganache.
• Pair the cake with black coffee, espresso or unsweetened tea to balance its sweetness.
• Vanilla ice cream is an optional accompaniment for especially rich servings.
• Keep garnishes restrained; a little plain coconut or chocolate is more in keeping with the recipe than nuts.

How to Store, Freeze and Make This Mounds Cake Ahead

Because the coconut filling contains milk and the ganache contains cream, store the assembled cake covered in the refrigerator rather than at room temperature. Making it a day ahead is particularly useful: the layers stabilize overnight and become easier to portion.

• Refrigerate the cake promptly after assembly and keep it at 40°F or below.
• For quality and conservative storage, use the refrigerated cake within 3 to 4 days.
• To freeze, first chill or freeze the cake until the topping is firm, then wrap it airtight. Thaw it overnight in the refrigerator.
• Frozen cake is best within about 3 months; the coconut may lose a little spring and the ganache may look less glossy after thawing.
• Do not reheat the assembled cake. Allow it to rest briefly at room temperature before serving.

For general food-storage practices, consult the FDA’s food-storage guidance.