Cake Slice Costume Tutorial

This costume is actually a piece of cake! Your little one will look so sweet with this adorable costume made using light foam. The confetti is made with Poly Pellets to create a candy-like coating for the cake slice.

What you need to make this project

Cushion Foam 24″ x 72″ x .5"
Poly-Fil® Poly Pellets® Weighted Stuffing Beads 2 pound Bag
Foam Core Board
Plaster of Paris
Glue Gun
Electric Knife
Multisurface paints

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Poly-Fil® Poly Pellets® Weighted Stuffing Beads 2 pound Bag


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Soft Support Foam 72″ x 24″ x ½” thick


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Step One

Let’s make the sprinkles first. Place Poly-Pellets in a container, then add a small amount of multisurface paint to the container. Mix until the pellets are covered in paint. Lay the pellets on a sheet of wax paper to dry. When they are dry, pour them into a larger bowl to break up clumps and mix the colors together.

Step Two

Cut the foam to fit the length and width of the foam core board. Leave an open space in the middle where the “icing” will go. Hot glue the foam to the board. (Note: I used thick foam and sliced it in two to make the foam thinner. I advise that you use the 1/2″ foam to save time and keep the cake slice as light as possible.)

Repeat with the other side, but cut a square out of the middle for the child to have one arm out of the cake slice.

Step Three

Now let’s make the “icing”. Mix two parts of the Plaster of Paris mix with one part water. Stir until it has the consistency of frosting. Fill in the space between the cake slices with “icing”.

Step Four

Spread the Paster of Paris over a sheet of foam core board. Sprinkle the Poly-Pellets onto the wet plaster and gently push them into the wet plaster.

Step Five

When the plaster is dry, use hot glue to attach the three pieces of board together in a triangle shape. Cut two strips of Oly-Fun Fabric and glue them to make straps to hold the cake slice on the child’s shoulders. Cut pieces of foam to cover the front and back of the top of the cake, and hot glue those on.

Step Six

Cover the top of the cake slice with Plaster of Paris “icing” and spread the “sprinkles” on top, pressing them into the plaster.

Step Seven

While you wait for the plaster to dry completely, make a tube using Oly-Fun Fabric, and hot glue it to a headband. Cut a flame from Oly-Fun Fabric and glue it inside the tube. Now your piece of cake has a candle to go on top!