Cake of the Day: Geode Candy Cupcakes from ‘Nerdy Nummies’

Every day, Yahoo Food features delectable cakes. They taste good, they look good, and they’re made by good people — talented bakers from around the world. This week we’ll be sharing adorable creations from Rosanna Pansino of the popular YouTube baking channel, Nerdy Nummies and her new cookbook The Nerdy Nummies Cookbook: Sweet Treats for the Geek in All of Us. Check back to Cake of the Day for more geeky desserts!


Geode Candy Cupcakes (Photograph by Michael Schmidt)

By Rosanna Pansino

Geode Candy Cupcakes
Makes 24 cupcakes

THINK THESE ARE ALL ROCKS? THINK AGAIN. As a former rock collector (Nerd alert! We’ve got a nerd factor five in the building), I can say that some of my favorite mineral formations are geodes. Just about everyone has seen geodes, but do you know they’re made when pockets of gas are trapped inside of rock? Minerals form into the shapes of crystals along the interior, creating the solid structures you can crack open and look into! Geodes come in many colors and formations, so you can really get creative with these convincing snacks. See? Rocks are cool!

The things you’ll need:
White fondant
Chocolate fondant
3 cups sugar
1 cup water
Purple liquid food coloring
White Cake batter (see below)
1 tub (16 ounces) buttercream frosting
Assorted colors of hard candies (Jolly
Purple sanding sugar
Small glass bowls
Muffin tins
Brown cupcake liners


Photograph by Michael Schmidt

To make a geode, roll out the white and chocolate fondant into 1/8-inch-thick rounds about 5 inches across, making the chocolate one a little bigger [Image A]. Repeat this for a second geode (you can make more geodes if you’d like, as you will have leftover fondant and sugar syrup).

For each geode, line a small bowl with several layers of aluminum foil, crumpling the foil unevenly on the inside to make a unique rock-shaped shell [Image B].

Cover the aluminum foil with the chocolate fondant. Lay the white fondant on top of the chocolate [Image C].

In a medium saucepan, combine the sugar and water. Whisk constantly over low heat until all the sugar is dissolved. Add 4 drops of purple food coloring [Image D]. Whisk until the color is completely blended, and remove from the heat.

Spoon the purple sugar syrup into the fondant cups until almost full [Image E].

Completely cover your geodes with aluminum foil [Image F] and let sit for at least 12 hours, giving the sugar time to crystallize.


Photograph by Michael Schmidt

Take your geodes out of the foil enclosure. Over a bowl, puncture the center of the purple sugar with a sharp knife. Allow the liquid to drip out into the bowl and then carefully scrape out the excess sugar [Image G].

Prop the geodes, crystal side down, over a bowl for at least 2 hours to let the excess liquid drip out and the sugar crystals to dry [Image H]. I place them on top of lollipop sticks for this step.

Once the sugar in the center of the geodes is dry, trim off the excess fondant around the edges with a knife [Image I].

Preheat the oven to 350°F. Line 24 cups of 2 muffin tins with brown paper liners. (Or use 1 muffin tin and bake in batches.)

Prepare the White Cake batter (see below for recipe). Fill each muffin cup two-thirds full with batter.

Bake until a wooden pick inserted in the center of a cupcake comes out clean, 18 to 20 minutes.

Let the cupcakes cool completely before decorating.

Time to decorate!:
Frost the cupcakes with buttercream frosting.

Place the hard candies in plastic bags, dividing them by color. Use a hammer or rolling pin to crush the candies so you have large and small pieces [Image J].

Set aside 4 of the cupcakes. Over the remaining cupcakes, sprinkle the smaller pieces of hard candy all over the tops. Place the larger pieces of the hard candies in the center of the cupcakes to make crystal formations [Image K].

Dip the 4 reserved cupcakes in the purple sanding sugar. Carefully cut the geodes in half and place one half in the center of each cupcake [Image L].

White Cake

2 cups all-purpose flour
2 teaspoons baking powder
1/8 teaspoon salt
1 stick (4 ounces) salted butter, at room
¼ cup solid vegetable shortening
11/2 cups sugar
2 teaspoons vanilla extract
¼ teaspoon almond extract
5 large egg whites
¾ cup whole milk

Preheat the oven to 350°F. Grease a 9 x 13-inch metal baking pan and line the
bottom with parchment paper. (Or see the cupcake variation below.)

In a medium bowl, whisk together the flour, baking powder, and salt. Set aside.

In a large bowl, with an electric mixer, beat the butter and shortening until softened. Add the sugar and beat until light and fluffy, 3 to 5 minutes. Scrape down the sides of the bowl as needed.

Beat in the vanilla and almond extracts.

Add the egg whites, one at a time, beating well after each addition. Scrape down the sides of the bowl as needed.

On low speed, alternate adding the flour mixture and the milk to the butter
mixture, beginning and ending with the flour mixture.

Line 24 cups of 2 muffin tins with paper liners and fill two-thirds full with batter. (Or use 1 muffin tin and bake in two batches.) Bake at 350 °F until a wooden pick inserted in the center of a cupcake comes out clean, 18 to 20 minutes. Transfer to a wire rack to cool.

Reprinted with permission from Nerdy Nummies by Rosanna Pansino (Atria Books).


For more awesome cake inspiration, visit our Cake of the Day Pinterest board and get to pinning!

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