• In a large mixing bowl, whisk together sugar, flour, cocoa powder, baking powder, baking soda, salt. 
• Add eggs, milk, oil, vanilla, water and mix until smooth. The batter will be thin. 
• Pour batter in cupcake liners (About two thirds full).
• Bake at 350 degrees for 20-25 minutes or until as inserted toothpick in the center comes out clean.
• Allow the cupcakes to cool down completely.
• While the cupcakes are cooling, prepare the frosting: In a large mixing bowl, add melted butter, cocoa powder and mix until smooth.
• Gradually, add powdered sugar, while alternating with the heavy cream until light and fluffy.
• Mix in vanilla extract.
• Note: If frosting is too thin, thicken it by adding more powdered sugar. If icing is too thick, thin it out by adding a little more heavy cream.

Assembling

• Hollow out the center of each cupcake with an apple corer or a big decorating tip like Tip 1M. 
• Fill it with sprinkles. 
• Place a small piece of hollowed out cake on top to cover the hole.
• Attach Tip 1M to a piping bag and fill it with frosting.
• Ice a swirl of frosting on top pf each cupcake.
• Toss more sprinkles on top and enjoy!