Ninjago Full Sheet Cake Topper: How to Make One

A Ninjago full sheet cake topper is an edible printed image sized to cover the top of a sheet cake, usually made with frosting sheets or wafer paper. It gives a party cake a bold, tidy finish without complicated piping; the key is measuring the cake, choosing a food-safe image, and applying it to a smooth layer of frosting.

Ingredients

1 full-sheet edible frosting image featuring Ninjago artwork, sized to the cake (typically about 18 × 24 in / 46 × 61 cm; confirm the actual pan dimensions)
1 full-sheet cake, completely cooled (about 18 × 24 in / 46 × 61 cm)
4 cups (about 900 g) vanilla buttercream, for filling any gaps and covering the top
2 tablespoons (30 ml) light corn syrup or piping gel, optional, for smoothing small wrinkles on frosting sheets
1 teaspoon (5 ml) water, optional, for lightly dampening wafer paper on a fondant surface
1 cup (about 120 g) assorted colored sprinkles, optional, for the cake border

Instructions

Check the image and cake size. Buy or print a commercially prepared edible image made with food-grade ink on an edible frosting sheet or wafer paper. Confirm its dimensions against the actual top of the cake, not just the pan label; full-sheet pans vary. Keep the image sealed in its original packaging until you are ready to use it. Do not use ordinary printer ink or a standard paper printout as an edible decoration.
Cool and level the cake. Make sure the cake is fully cool before frosting, or the buttercream may melt and the image may slide. If the top is domed, trim it level with a long serrated knife. Place the cake on a firm board or serving tray that can support its weight.
Apply a smooth frosting layer. Spread about 3 cups (675 g) of buttercream over the top in an even layer, approximately ⅛–¼ inch (3–6 mm) thick. Smooth it with an offset spatula, filling crumbs and low spots. Save the remaining buttercream for the border. The surface should be level, with no exposed cake, but it does not need to be perfectly polished because the image covers it.
Prepare a frosting sheet. If using a frosting sheet, check whether its backing has loosened. If it remains firmly attached, place it flat in its sealed package for a few minutes at room temperature, then gently flex the backing; do not pull hard or crease the image. Remove the backing only when ready to apply. Avoid refrigerating an unsealed sheet, since condensation can make the colors run.
Position the image. Hold the image by its edges and align it above the cake before lowering it. Set one edge down first, then gradually lower the rest onto the buttercream. Smooth from the center outward with clean, dry fingertips or a fondant smoother, using light pressure to release air bubbles. Do not stretch the sheet. If a small wrinkle remains, dab it sparingly with a little piping gel or corn syrup and smooth gently; too much liquid can dissolve the image.
Use wafer paper differently, if applicable. Wafer paper is firmer and less flexible than a frosting sheet, and its colors may look less vivid. It works best on a fondant-covered cake or a dry, firm frosting surface. If needed, brush the underside very lightly with water—just enough to help it adhere—and place it promptly. Avoid wet buttercream and excess moisture, which can cause wafer paper to buckle or curl.
Finish the border. Pipe a border around the image with the remaining buttercream, or add sprinkles around the edge. Keep decorations off the printed design so faces and lettering remain visible. If the image is slightly smaller than the cake, use the border to cover the gap; do not force a too-large sheet over the sides.
Let it settle and serve. Leave the decorated cake at cool room temperature for about 15–20 minutes so the sheet can lie flat against the frosting. If the room is warm or the cake needs longer storage, refrigerate it in a tall cake box. Bring it out shortly before serving, avoiding sudden exposure to humid air that may cause condensation.

Tips

Use the right cake measurements. A pan sold as a full sheet may differ by manufacturer. Measure the frosted top and order the image to fit, or have it trimmed with clean scissors before removing its backing.
Choose the sheet for the surface. Frosting sheets are flexible and give stronger, clearer color on buttercream. Wafer paper is a useful alternative for a firmer surface but is more prone to curling and has a drier texture.
Keep moisture controlled. Do not brush a frosting sheet with water. Piping gel or corn syrup is optional and should be used sparingly; excessive moisture can blur colors or make the sheet gummy.
Check food-allergen and handling details. Read the edible-image packaging for ingredients, allergens, storage instructions, and printing suitability. Keep the sheet covered and handle it with clean, dry hands.

Serving Suggestions

Serve the decorated cake at room temperature for the softest texture and easiest slicing. Cut into 24 party-size portions, or make smaller squares for a larger gathering. A sharp, clean knife helps keep the image and buttercream border neat; wipe the blade between cuts if frosting builds up. Pair the cake with milk, coffee, tea, or fruit, and place candles around the printed design rather than directly on it.

Variations

For a cleaner graphic, use a single printed image on white vanilla buttercream. To match a party palette, tint the border buttercream with gel food coloring and add coordinating sprinkles. A chocolate sheet cake works just as well, but cover it with a light-colored frosting layer first so the image’s colors remain clear. If you cannot find a full-sheet image, use two smaller food-safe images and align them carefully; cover the seam with a narrow piped line or a border of sprinkles. For a fondant finish, cover the cake with rolled fondant and use a light touch of water beneath wafer paper, or follow the image maker’s instructions for frosting sheets.

Storage and Reheating

Because this is a frosted cake, refrigerate it within 2 hours of serving or decorating if it contains perishable filling or frosting, and keep it covered in a cake box to protect the image from moisture and odors. A frosted cake generally keeps for about 3–4 days in the refrigerator, though the printed sheet may soften, fade, or become tacky over time. For best appearance, apply the topper on the day you plan to serve the cake, or follow the image package’s specific storage guidance. Freeze leftover cake in airtight portions for up to 2 months; thaw overnight in the refrigerator, still wrapped, then let it stand briefly before serving. Do not reheat decorated cake—the image and frosting can melt or become damaged.

Frequently Asked Questions

Can I put an edible image on buttercream?
Yes. A smooth, slightly tacky layer of buttercream is a good base for a frosting sheet. Apply it after the frosting has been spread and leveled; a crusted or very dry surface may not grip the sheet as well.

How far ahead can I put the topper on?
For the sharpest colors and smoothest appearance, apply it the day of serving. It can be applied earlier if necessary, but refrigeration, humidity, or condensation may soften the sheet. Follow the image manufacturer’s storage recommendations.

Why is my edible picture wrinkling or bubbling?
Wrinkles can come from lowering the sheet unevenly, too much moisture, or a lumpy frosting surface. Smooth from the center outward with light pressure, and use only a very small amount of piping gel for a minor wrinkle. Small air bubbles may settle; avoid puncturing the design unless the image supplier recommends it.

Can I print the picture at home?
Only use a printer designed for edible printing with food-grade ink and edible sheets. Never put edible paper or frosting sheets through an ordinary printer, even if the ink cartridge is new, because the printer may contain residues not meant for food.

Can I use a Ninjago picture from the internet?
Choose an image supplied by a licensed edible-image provider or one you have permission to reproduce. Make sure it is printed with food-grade ink on a sheet explicitly labeled edible; a regular paper topper should be kept on a food-safe barrier and removed before serving.

What if the topper is smaller than my cake?
Center it and decorate the exposed edge with a buttercream border, piped stars, or sprinkles. If it is larger, trim it to fit while it is still on its backing, using clean scissors and taking care not to cut through the design area.

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