DIY Wedding Cake with Marshmallow Fondant

When my daughter and son-in-law got married, and as a Mama-baker with a very artistically talented younger daughter, you can correctly guess that our kitchen didn’t remain quiet in the days leading up to the wedding.

We created two Do It Yourself (aka DIY) wedding cakes: a 3-tiered watercolor pastel drip wedding cake and a surprise groom’s cake in the shape of a TARDIS from the long-running BBC TV series, Doctor Who. Plus we made several desserts for a pre-wedding Happy Hour for our out-of-town guests.

Actually, let me correct that - we had three wedding cakes at the celebration. Since the wedding was held on my husband's & my 34th wedding anniversary, our girls created a surprise anniversary cake for us, too. They're so sweet (and sneaky)!

One element we used is marshmallow fondant instead of commercially made fondant out of a box. It is a huge improvement, both in taste and usability. Also, using styrofoam instead of cake for some of the tiers brought down the baking time and cost considerably.

The finished design, with its hand-painted pastel watercolor stripes and fresh flowers, is easy and beautiful!

An award-winning cake decorator knows how to design cakes

My younger daughter is a talented cake designer and decorator, and it’s not just me that says it (although as her mama, I’m her biggest cheerleader). In Middle and High School, she entered our local County Fair’s cake decorating competition several years in a row, and always won First Place, and even Best in Show.

Over the years she has made custom birthday cakes, graduation cakes, and baby shower cakes, as well as her fantasy cakes for the competitions. We’re a great team, she and I - I bake the cakes and she decorates them. Fun times.

Cake sculpting secrets

When making a sculptured cake like those above, you need an interior structure that's firm enough to be able to stand up in ways other than just in a layer. There are two ways you can go - fully edible or partially edible.

[ ** insert tires screeching sound here ** ] (What do you mean, partially edible?!)

For cake decorating competitions, where the cake will be sitting out for a long time (such as with County or State Fairs), frequently styrofoam will be used on the inside instead of cake. It's covered with fondant to serve as the canvas from which to start decorating. Obviously, styrofoam isn't edible, but it is cheap and easy to carve, and doesn't wilt or spoil over the days of competition.

If you watch those baking shows about fancy (and fully edible) sculpted cakes (like Ace of Cakes), you’ll discover that a version of Rice Krispies Treats are frequently used for structure, especially for large cakes. They’re cheaper and easier to make than cake layers, plus they’re also easy to carve as they don't crumble as a baked sponge cake would. That's what we used for the base of our groom's TARDIS cake.

Our DIY wedding cake design

When my older daughter got engaged, my younger daughter and I knew that we were going to make her wedding cake. Our in-house cake decorator designed a lovely 3-tiered cake with a simple, yet elegant theme of hand-painted pastel watercolor stripes with fresh flowers festooned around it.

We also made a strategic decision: only the top tier would be edible.

I live in a small apartment without the walk-in refrigerator/freezer that commercial bakeries have…don’t judge.

What you need

A wedding cake generally consists of 2 or more tiers of layer cake covered in fondant icing and decorated in many ways, from simple to elaborate. We eliminated the cake from 2 tiers, opting to use styrofoam rounds instead. Here are the specific elements we used:

Element #1: Cake for the top tier

For the top layer, I wanted a cake recipe that I knew the bride loved, namely Chocolate Kahlua Cake. We baked three 6-inch round layers, and filled them with Chocolate Buttercream Frosting to stand 6-inches high. Simple and delicious.

Element #2: Styrofoam for the middle and bottom tiers

The lower two tiers would be two 4-inch high, 8-inch and 12-inch styrofoam rounds, double stacked to stand 8-inches high. This simplified the baking (and the cost) tremendously. My daughter has lots of experience decorating styrofoam "cakes" after all.

Element #3: Fondant icing

Fondant, essentially edible clay, is one of the basic elements in cake decorating. It covers the cake, and acts like a canvas that's then decorated. However, one complaint that I always have with store-bought fondant is that it basically tastes like soft plastic. It’s pretty and all, but it truly lacks in the deliciousness department. So we made homemade marshmallow fondant instead.

This marshmallow fondant is smooth and pliable, is easier to roll out, and most importantly, it tastes great. All you need are a box of ready-made fondant, marshmallows, powdered sugar, and vegetable shortening.

Our marshmallow fondant recipe also had another plus - because we fixed the boxed fondant with marshmallows, it stretched the amount of coverage by 300%, and that really brought down the overall cost. Win!

Element #4: Decorating items

For our wedding cake, we used food color gel mixed with a bit of vodka for the painted stripes, and fresh flowers and greenery, some gilded with gold luster dust. It's a simple, yet beautiful design concept.

How to make marshmallow fondant

The steps to making a marshmallow fondant recipe are straightforward:

1. Sift the powdered sugar into a large bowl. Prepare to use half in the marshmallow mixture.
2. Melt the marshmallows in the microwave or on the stove.
3. In a stand mixer with a dough hook attachment, combine the melted marshmallows with vegetable shortening, then slowly mix in half of the powdered sugar in 1 cup increments, mixing until smooth. Add color, if desired.
4. Heat the ready-made fondant just a bit to soften.
5. Place the marshmallow mixture in the bowl with the remaining powdered sugar (greasing your hands with vegetable shortening helps), then add the softened fondant and knead everything together until the sugar is mostly incorporated
6. Transfer the marshmallow fondant to a powdered-sugar-dusted work surface. Smear your hands with vegetable shortening, and knead and pull the fondant like taffy until it's stretchy and smooth.
7. If there are rough spots or it's tearing, heat the fondant in the microwave for 30 to 40 seconds until it's hot. Keep pulling the fondant until it stretches without breaking.

Pro Tips: Making and using fondant

Since I'm the baker and not the decorator, I asked my younger daughter for her thoughts on using this marshmallow fondant. Her advice:

• Don’t frost beneath the fondant too thickly (called crumb coating)  as it makes the sides too soft
• Definitely chill the cake before and after crumb coating the sides before the fondant goes on
• Store the fondant in an airtight bag at room temperature. It will keep for months. To use again, reheat and knead the fondant well until it's stretchy before each use.

When she made the fondant for the wedding cake, she ended up using more powdered sugar than the recipe called for, especially at the end during kneading. It was really humid that day, and this factor depends on climate. She still got some “elephant skin” and tears, but shortening mostly fixed these problems. It happens, folks!

Questions asked and answered

Here are some questions you might have...

How to make a DIY wedding cake

Now that the fondant is made and we have gathered the decorations, it's time to assemble the wedding cake itself.

Step 1: Crumb coat the tiers

After chilling the top-tier layer cake (in this case the 6-inch 3-layered Kahlua Cake), it's crumb-coated by frosting the sides with a thin layer of vanilla buttercream (photo 1). The other 2 styrofoam layered tiers are also crumb-coated with vanilla buttercream.

Step 2: Apply the fondant

If necessary, reheat and knead the fondant well until it's stretchy and pliable before each use. Roll it out about ⅛-inch thick in a size larger than the tier to be covered (photo 2).

Step 3: Decorate the tiers

The tiers are ready to decorate how you see fit. For our DIY wedding cake, my daughter used food color gel mixed with a bit of vodka to paint on the stripes. She painted them bottom-to-side on the top tier and top-to-side on the bottom tier (photo 4). The middle tier was left white.

My younger daughter is a brilliant designer, and I'm glad we're able to make incredible cakes for those we love.

Using creativity, ingenuity, and perhaps even a secret element, you can make your own celebration cake, and cover it with delicious marshmallow fondant. It's truly a labor of love with beautiful and delicious results for those you love!