Go Back
+ servings
a white round baking dish with hot chocolate pudding cake, topped with minin marshmallows

Hot Chocolate Sundae Cake

Hot Chocolate Sundae Cake - This ultra decadent chocolate cake magically creates it's own hot chocolate sauce as it bakes! Top it off with a generous dollop of Reddi-wip, it's even better than warming up to a mug of hot chocolate!
Course Dessert
Cuisine American
Prep Time 15 minutes
Cook Time 24 minutes
Total Time 39 minutes
Servings 10 servings
Calories 273kcal
Author Amy


  • 3/4 cup granulated sugar
  • 1/4 cup baking cocoa
  • 1 cup flour
  • 2 tsp baking powder
  • 1/4 tsp salt
  • 1/2 cup milk
  • 4 Tbsp butter melted
  • 1 egg yolk
  • 2 tsp vanilla
  • 1/2 cup semi-sweet chocolate chips
  • 1/2 cup marshmallows
  • 1/3 cup brown sugar
  • 1/3 cup hot chocolate mix
  • 1 cup hottest tap water


  • Preheat oven to 350 degrees. Spray an 9”x9” pan with nonstick spray.
  • To a medium sized mixing bowl add granulated sugar, ¼ cup of baking cocoa, flour, baking powder, and salt. Stir until combined.
  • To a separate bowl add milk, melted butter, egg yolk, and vanilla. Whisk until combined.
  • Pour milk mixture into the flour mixture. Stir until well combined. Batter will be thick. Add chocolate chips and marshmallows to the cake batter and stir to incorporate. Place cake batter in prepared 9”x9” pan and spread to edges.
  • I used to the same bowl used to make the cake batter in for this next step. Add brown sugar and 2 packages Swiss Miss Hot Chocolate envelopes to bowl and mix. Sprinkle brown sugar mixture evenly over the top of cake. Do not stir.
  • Measure 1 cup hottest tap water into a measuring cup. Add remaining two envelopes of Swiss Miss Hot Cocoa to water and stir until combined. Pour Swiss Miss hot chocolate over the top of the cake. DO NOT STIR.
  • Bake cake for 22-24 minutes. The cake will look a little underdone and that’s exactly how it should look. Marshmallows should be golden brown.
  • Cool cake for 10 minutes. Serve warm with a generous amount of Reddi-wip topping.


This cake is best served hot with whipped cream or vanilla ice cream! 
Store leftovers in the fridge and microwave before serving!


Calories: 273kcal | Carbohydrates: 45g | Protein: 3g | Fat: 10g | Saturated Fat: 6g | Cholesterol: 34mg | Sodium: 243mg | Potassium: 123mg | Fiber: 2g | Sugar: 31g | Vitamin A: 188IU | Calcium: 92mg | Iron: 2mg