How to Make a Completely Edible Castle Cake with Frost Form
Creating a fully edible castle cake might look intimidating — but with Frost Form kits, clean ganache edges, and a little planning, you can build a show-stopping centerpiece that’s surprisingly achievable.
This tutorial walks you step-by-step through stacking, filling, and decorating your castle cake from start to finish.
Click here to get all the sizes you need to make your own Castle Cake!
Tools & Supplies
Tools
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Frost Form kits
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3-inch round (preferably two)
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Acetate sheets
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Ruler
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Masking tape
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Large square cake board
- Food-safe paint brush
Ingredients
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Cakes (your preferred flavor)
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Buttercream (for filling)
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White chocolate
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Oil (for mock ganache)
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Candy Melts / Deco Melts
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Fondant
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Optional: edible luster dust + vodka (or alcohol-based solution)
Step 1: Stack & Fill the Cakes
3-Inch Towers (Turrets)
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You can use cupcakes inside the 3-inch kits to help fill the space.
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Stack using buttercream or ganache only for stability.
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Avoid soft fillings — structure is key for tall elements.
5-Inch Round (Main Tower)
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Stack and fill inside the Frost Form liner and crumb cutter for sharp, clean edges.
6-Inch Square (Castle Base)
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Stack this one free-hand.
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Take extra time ensuring it’s stacked evenly — this is the foundation of your castle.
❗️Important Note: Tiered Cakes need structural support. You will need to dowel the square cake for added support!
Learn how to dowel tiered cakes with Frost Form here
Step 2: Remove Liners & Optional Crumb Coat
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Carefully remove all liners.
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Wash and dry the forms immediately.
Optional but recommended:
Apply a very light crumb coat and chill in the fridge until firm. This helps prevent crumbs in your ganache layer.
Crumb coating your cakes also helps prevent your cakes from “floating” (detaching from the base). So be sure to seal in the bottom of your cake with buttercream or ganache.
Step 3: Make the Ganache (Mock Ganache)
For a cake this size, you’ll need a large batch.
Mock Ganache Recipe
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2173g white chocolate
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494g oil
This creates a smooth finish, perfect for sharp edges.
Important Tips
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Use a pourable consistency ganache. (Mock Ganache or Butter Ganache)
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Either prepare one extra-large bowl or divide into two smaller batches.
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Let the ganache cool to 26–28°C (79–82°F) before pouring into the forms.
Fill your forms and place them in the fridge or freezer until completely set.
Step 4: Make the Turret Roof
This step creates the pointed castle roof — and yes, it’s completely edible!
1. Prepare the Acetate
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Cut 2 acetate sheets to 25cm (10 inches).
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Roll into a cone with at least an 8cm (3.15 inches) diameter base.
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Make sure the tip is tight.
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Secure with masking tape.
2. Fill the Cone
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Melt your Candy Melts either in the microwave, stirring between bursts or with a Ban Marie on the stove.
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Place the cone into a tall glass for support.
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Pour in the melted candy melts and rotate the cup, letting the excess flow back into the bowl.
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Refrigerate for 5 minutes, then add a second coat & refrigerate again.
This reinforces the structure.
Step 5: Assemble the Castle
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Remove all cake formers and liners.
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Place the 6-inch square onto a large square cake board.
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Stack your 5-inch round tier in the center of the square cake.
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Position the 3-inch turrets on the corners or where desired.
Step 6: Add Fondant Details
Time to bring it to life!
Cut & Attach
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Door
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Windows
Roll thin ropes of fondant to:
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Frame the door
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Outline windows
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Add brick or panel detail
Attach with a small amount of water or edible glue.
Step 7: Add the Turret Roofs & Finish
Remove & Straighten
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Once the cones are fully set, gently remove tape and peel off the acetate.
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Warm a plate in the microwave.
Press the cone bottom onto the warm plate and gently twist until perfectly level.
Now you have a clean, even turret roof.
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Immediately place the turret roof cones on top of the 3-inch towers while the candy melts are still melted from the hot plate.
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Ensure they sit level and secure.
To finish, mix gold luster dust with a small amount of vodka (or another alcohol-based solution) to create a paint-like consistency.
Lightly brush the mixture over the turret roofs for a metallic gold finish.
And Voilà! It couldn’t be any easier to make a Castle Cake that will leave your guests in shock and awe!!
Click here to order the kits you need to get started!
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