In the bowl of a stand mixer, cream the butter until smooth. Slowly add the powdered sugar, vanilla and salt, mixing until fully combined.
5-6 cups powdered sugar, 2 sticks of unsalted butter, pinch of salt, 1 teaspoon vanilla extract
Add blue food coloring and mix until you reach your desired ocean water shade.
Blue food coloring
Frost the entire cake and smooth out the surface and edges using a cake scraper until you have an even layer of frosting.
Use a toothpick or skewer to outline one corner of the cake as your beach. Sprinkle graham cracker crumbs in that corner and gently pat them to create sand. Use a bit of extra frosting to create waves with a small offset spatula.
1/2 cup graham cracker crumbs
Transfer remaining frosting to a piping bag with a star tip and pipe a border around the cake.
Place the pirate ship in the water and smear frosting up its sides to mimic gentle waves. Set the palm trees and treasure chest on the beach. Fill the chest with gold coin sprinkles.
Add a pirate sign, banner other other props in the sand and around the cake if desired.
Optional: Spray the cake with shimmer for an ocean shine.
Blue cake shimmer
Notes
Chill your cake before decorating. A cold cake is easier to frost and less likely to crumble.
Level the top if necessary. You want a flat surface so the beach and water sit evenly.
Don’t stress over smooth frosting. The waves and decorations will cover most of it.
Practice your piping border on parchment paper first to get the feel for the pressure.
If your frosting gets too soft while decorating, pop it in the fridge for a few minutes.