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Mermaid Birthday Ice Cream Cake

Mermaid Ice Cream Birthday Cake

A Mermaid Ice Cream Birthday Cake with fondant mermaid tails and edible seashells, starfish, and seahorses. Perfect for a mermaid, beach, or ocean themed birthday party!
Prep Time 30 mins
Cook Time 10 mins
Chill Time 4 hrs
Total Time 4 hrs 40 mins
Course Dessert
Cuisine American
Servings 12


  • 9x13-inch glass dish or metal pan
  • silicone molds for mermaid tails and ocean shapes
  • toothpicks
  • food grade paintbrushes, paint palette


For the Fondant Mermaid Tails and Ocean Shapes:

  • white fondant or gum paste
  • Food coloring gel

For the Crust:

  • 2 1/2 cups crushed chocolate sandwich cookies (such as Oreos)
  • 1/2 cup melted butter (1 stick )
  • 1/2 cup granulated sugar

For the Ice Cream:

  • 1-1 1/2 gallons vanilla ice cream, softened (depending on the depth of the pan)
  • Food coloring gel (if desired)

For the Hot Fudge:

  • 2 cups powdered sugar
  • 2/3 cups semisweet chocolate chips
  • 12 ounce can evaporated milk
  • 8 tablespoons butter (1 stick)
  • 1 teaspoon vanilla extract

For the Topping:

  • 8 ounces of Cool Whip (thawed per package directions)
  • Food coloring gel

For the Decorations:

  • graham crackers (crushed to crumbs)
  • pearlized Sixlets candies


Make the Fondant Mermaid Tails and Ocean Shapes:

  • Tint the white fondant or gum paste with food coloring gel as desired. Press fondant into silicone molds. Slip molds into freezer for several minutes before removing the shapes from the molds.
  • Set shapes aside to dry out at room temperature. For the mermaid tails, insert a toothpick into the flat bottom before allowing them to dry so they will stick into the cake better.
  • When shapes have dried, brush with luster dust using a food grade paintbrush, if desired.

Make the Crust:

  • Combine 2 cups crushed cookies with melted butter and sugar.
  • Press into a 9x13-inch pan. Freeze for 15 minutes.

Color the Ice Cream:

  • Divide ice cream into 3 medium bowls. Color as desired.
  • Scoop alternate colors on top of crust until all ice cream has been scooped. Carefully spread the ice cream evenly, smoothing the surface with a silicone spatula. Freeze for 3 hours.

Make the Hot Fudge:

  • Combine the powdered sugar, chocolate chips, evaporated milk, and butter in a saucepan and bring to a boil for 8 minutes, stirring frequently. Remove from heat and stir in the vanilla. Cool to room temperature.
  • Spoon the fudge sauce on top of the ice cream layer and smooth with a silicone spatula. Freeze until firm.

Add the Topping:

  • Spread a layer of Cool Whip across the surface of the cake.
  • Place a portion of the Cool Whip in a small bowl. Gently fold in blue or teal food coloring gel. Spread the colored Cool Whip on one corner of the cake and swirl it into the white toward the corner diagonal to the colored Cool Whip.
  • Carefully spread the two sides until the meet in the middle and then swirl them together to create the illusion of waves.

Decorate the Cake:

  • Immediately before serving, add some graham cracker crumbs in one corner (on top of the white Cool Whip) to represent the sand on the beach.
  • Place fondant seashells and starfish as well as Sixlets on the crumbs. Arrange the seahorses in the water at the shore. Insert mermaid tails in the deeper part of the ocean.


For Brownie Crust, see Brownie Peppermint Ice Cream Cake
You're Gonna Bake It After All
Keyword American, birthday, cake, dessert, frozen treat, gluten free, ice cream, party