Simple step-by-step directions for making a beautiful sand castle cake coated with ground cookie crumbs.

I was sure this cake was going to be a disaster. Right up until the night before the party when I assembled, frosted, and coated it in cookie crumbs, I was pretty sure I would be running to the grocery store for store-bought cupcakes to toss my white chocolate shells onto during a mad dash to the party.

Thankfully I was wrong. The cake was much easier than I thought it would be, and looked even better than expected. Much easier than the Sock Monkey Cake I made 6 months ago. To make things simple, I baked the cake a week early, wrapped it in plastic and foil, and froze it. I finished the cake the night before the party. The look on my birthday girl’s face when she saw her cake in the morning was priceless. Her exact words were, “Mom, I knew it was going to be good, but I didn’t know it was going to be THIS amazing!”


Here’s what you’ll need to do…

You probably have all the pans and dishes to make a sandcastle cake, so don’t go buy new ones. I simply went through my cabinet stacking pans on top of each other until I was happy with the “castle” shape. The pans and dishes above happened to work well, but so would many other combinations. You could make 1 cupcake for the top layer, or square baking dishes for the bottom layer, for example.

The night before:

After baking, freezing, and thawing, I leveled any domes with a serrated knife. I then rewarded myself by eating the scraps along with a glass of Pinot Grigio – an important step. After I stacked the cakes I decided I wanted a little more height. I happened to have a small pound cake in the freezer, so I cut it into a square for the second to last layer. This is not necessary, however.


You can be much more relaxed with frosting this cake than others, as it is going to be covered by crumbs anyway. It’s a great cake if you’re intimidated by pastry bags and tips. If you can spread butter, you can do this! An offset spatula is the best tool for spreading frosting.

Chevron paper straws and one piece of fun scrapbook paper make cute castle flags. Cut out two flag shapes from the paper and use glue and staples to sandwich around the straw. The staples were barely noticeable over the silver paper.
I made white chocolate seashells to decorate the cake. You could also add a mermaid toy, Swedish fish, or treasure to the cake.

Yield: about 24 servings

Sandcastle Cake Recipe

Prep Time 30 minutes
Cook Time 40 minutes
Additional Time 2 hours
Total Time 3 hours 10 minutes

How to make a beautiful sandcastle birthday cake.

Sandcastle Cake Recipe


  • 1 cup of white chocolate chips and a candy mold for shells (optional)
  • 2 boxes cake mix or equivalent cake recipe (I recommend Organics brand, which can be found at natural foods stores).
  • Frosting for two cakes
  • 1 box of wafer cookies (I used a box of Trader Joe's toasted coconut cookie thins plus 2 handfulls of animal crackers, but vanilla wafers or graham crackers are fine too.)
  •  2 to 4 sugar ice cream cones
  • 2 to 4 cake ice cream cones
  • sprinkles or other decorations (plastic mermaids, fish, Swedish fish, would all be fun)


  1. Make white chocolate shells early so you have one less thing to worry about. Melt chips in a microwave safe bowl at 20 second intervals, stirring between the intervals, until chips have melted. Cool slightly and then pour into a pastry bag or plastic zipper bag. Snip off the tip and carefully pipe the white chocolate into the candy mold. Tap the mold on the counter repeatedly to release air bubbles. You will see little bubbles come to the surface. Place in the refrigerator to harden. Store in the refrigerator until ready to use. I piped a sea fan shape onto a piece of wax paper as well.
  2. Make cake batter according to recipe instructions and preheat the oven to specified temperature. Butter and lightly flour your cake pans. Pour batter into the prepared pans/dishes and smooth with a spatula. Bake according to recipe directions, but note that smaller baking dishes may cook more quickly and should be checked on frequently. Remove from oven when a toothpick inserted comes out clean. Cool on a cooling rack and remove cakes from pans. If making early and freezing, cool completely, wrap in plastic wrap and then again in foil and freeze. Otherwise you can leave cakes unfrosted and uncut for a day or two.
  3. Prepare frosting according to package directions. Cut any domes on the cakes off with a serrated knife so that the tops and bottoms are flat. With an offset spatula, frost the bottom layer of cake. Add the next layer and frost. Continue frosting and building your cake. Sometimes it's frosting goes on my smoothly after chilling the cake in the freezer for a few minutes.
  4. Place cookies in the bowl of a food processor. If your frosting is very wet you should wait until party day to add the crumbs so that they don't get mushy. My frosting was quickly forming a "crust" so I added the crumbs right after frosting the cake. Pulse until all the cookies are finely ground. Gently press the crumbs into the frosting.
  5. If making the flag towers, carefully cut 1/2" off the tips of sugar cones. Insert the wide end of the sugar cones into the tops of the cake cones with cake cones standing right in front of the cake. Insert flags into sugar cone holes. Add any decorations such as sprinkles, toy mermaids or fish, treasure, or white chocolate shells.