Preheat the oven to 350°F. Grease and flour a 12-cup Bundt pan or use MIRACLE PAN RELEASE. Set aside.
In a large bowl, combine the cake mix, melted ice cream, and eggs with an electric mixer just until combined. Pour the batter into the prepared pan, smoothing out the top with a spatula.
Bake for 38-42 minutes or until the edges just start to pull away from the pan. Allow the cake to cool in the pan on a wire rack for 15-20 minutes.
Carefully place a wire cooling rack over the top of the cake pan and invert the cake onto the rack, removing the cake from the pan. Allow it to cool completely.
Transfer the cooled cake to a serving platter or cake stand.
For the frosting
Sift the powdered sugar and cocoa into a medium bowl and set aside.
Heat the marshmallows, butter, and milk in a saucepan over low heat until the marshmallows are melted. Remove the pan from the heat and stir in the powdered sugar mixture. Add the vanilla. Stir until the frosting is smooth and shiny.
To assemble the cake
Use the frosting at once to top the cake. Top the cake with sprinkles or nonpareils, if desired.
Allow the frosting to cool and set before slicing and serving.
Notes
Use melted ice cream that is at room temperature. This will ensure that it mixes well with the other ingredients and creates a smooth batter.
Make sure to grease the bundt pan well before pouring in the cake batter. You don't want the cake to stick to the pan when you try to remove it.
Don't overmix the batter! Mix until just combined to avoid overworking the gluten in the cake, which can result in a tough texture.
Let the cake cool slightly in the pan before trying to remove it. This will help it keep its shape and prevent it from falling apart.
Feel free to experiment with different flavors of ice cream to create new and interesting variations of the cake.
Don't worry if the cake looks a little lumpy or uneven before baking. The melted ice cream can create a slightly lumpy texture, but it will smooth out as the cake bakes.
Serve the cake with your favorite toppings, such as whipped cream, fresh berries, or a drizzle of chocolate sauce.
Have fun with it! Melted Ice Cream Bundt Cake is a fun and easy dessert that's perfect for experimenting with new flavors and toppings.