Walmart Mug Cakes

Name: Walmart Mug Cakes
Cook time: 35 min
Total time: 35 min
Cuisine: American
Ingredients: 1 pouch Betty Crocker Mug Treats Rainbow Chip Cake Mix; 3 tbsp water; White chocolate ganache (recipe below); 2 cups buttercream frosting; Food coloring in pink, teal, and violet; 1 large marshmallow; Pink sanding sugar; Sprinkles; Fondant unicorn horn; 1 cup white chocolate chips; ½ cup heavy whipping cream; ⅓ cup butter, cubed; Pink, gel-based food coloring