Spiced Rum Molasses Chocolate Cake with Rum Buttercream

By AislePrompt Editorial · Published 2026-06-24 · Updated 2026-06-24

A moist chocolate cake enriched with molasses and spiced rum, topped with a creamy rum-infused buttercream frosting. This recipe, ready in about 55 minutes, layers all-purpose flour, unsweetened cocoa powder, baking powder into a dessert worth slowing down for — great for weekend baking, holiday tables, or any time you want a sweet payoff at the end of a meal. Each serving lands at about 420 calories and feeds 8, so it slots into a weekend bake or a special-occasion dessert tray. Tap "Plan a meal with the AI" below to drop this recipe into your week and send the ingredients straight to Instacart. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.

Ingredients

• 1 3/4 cups all-purpose flour
• 3/4 cup unsweetened cocoa powder
• 1 1/2 tsp baking powder
• 1 1/2 tsp baking soda
• 1 tsp salt
• 1 tsp ground cinnamon
• 1/2 cup (1 stick) unsalted butter
• 1 1/2 cups granulated sugar
• 1/2 cup packed brown sugar
• 2 large eggs
• 2 tsp vanilla extract
• 1/4 cup molasses
• 1/4 cup dark spiced rum
• 1 cup buttermilk
• 2 cups powdered sugar
• 1/2 cup softened unsalted butter for frosting
• 2 tbsp dark spiced rum for frosting
• 2 tbsp unsweetened cocoa powder for frosting

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Instructions

1. Step 1: Preheat oven to 350°F. Grease and flour two 8-inch round cake pans.
2. Step 2: In a medium bowl, sift together 1 3/4 cups all-purpose flour, 3/4 cup unsweetened cocoa powder, 1 1/2 tsp baking powder, 1 1/2 tsp baking soda, 1 tsp salt, and 1 tsp ground cinnamon. Set aside.
3. Step 3: In a large bowl, cream 1/2 cup unsalted butter, 1 1/2 cups granulated sugar, and 1/2 cup packed brown sugar with an electric mixer on medium speed until light and fluffy, about 3 minutes.
4. Step 4: Beat in 2 large eggs one at a time, then add 2 tsp vanilla extract, 1/4 cup molasses, and 1/4 cup dark spiced rum, mixing until combined.
5. Step 5: Alternately add the dry ingredients and 1 cup buttermilk to the wet mixture in three parts, starting and ending with dry ingredients. Mix each addition just until incorporated.
6. Step 6: Divide batter evenly between the prepared pans and bake for 30-35 minutes until a toothpick inserted in the center comes out clean.
7. Step 7: Cool cakes in pans for 10 minutes, then turn out onto wire racks to cool completely.
8. Step 8: For the buttercream, beat 1/2 cup softened unsalted butter until creamy. Gradually add 2 cups powdered sugar, 2 tbsp unsweetened cocoa powder, and 2 tbsp dark spiced rum, beating until smooth and spreadable.
9. Step 9: Frost the cooled cakes with the rum buttercream and serve slices to enjoy the rich molasses and spiced rum flavors.