Green Slime Cupcakes

Cupcake topped with frosting and green and black sprinkles, with another swirl of black and green frosting on top with a green candy ball to finish. Halloween decor is in the background.

These Green Slime Cupcakes use a boxed cake mix for a quick baking shortcut, with homemade vanilla buttercream and a fun decorating technique that creates a delightfully messy monster-inspired finish.

Course Dessert

Cuisine Halloween

Prep Time 1

Cook Time 20

Total Time 1 20

Servings

Calories 720kcal

Author Michelle Ordever

Equipment

Ingredients

For the Cupcakes

15.25 ounce box vanilla cake mix
3 large eggs
1 cup whole milk
½ cup unsalted butter softened
neon green gel food coloring as needed

For the Frosting

2 cups unsalted butter softened
5 cups powdered sugar icing sugar
5 tablespoons heavy cream double cream
3 teaspoons pure vanilla extract
black gel food coloring as needed
neon green gel food coloring as needed

Halloween Decorations

2 ounces package green sprinkle mix
2 ounces package black sprinkle mix
2 tubes Wilton Green Sparkle Gel
12 green gumballs

US Customary - Metric

Instructions

Make the Cupcakes

Preheat the oven to 350°F (180°C / Gas Mark 4). Line cupcake pans with 12 black cupcake liners and set them aside.
Using an electric standing or hand mixer, beat the cake mix, eggs, milk, and butter until combined and smooth.
Add a few drops of neon green gel food coloring and mix until evenly colored. Add more coloring as needed to achieve a vibrant green.
Use an ice cream scoop to divide the batter between the cupcake liners. Fill about ¾ full.
Bake in the preheated oven for 20 minutes or until an inserted toothpick comes out clean.
Remove the cupcakes from the oven and leave to cool in the pan for 5 minutes before transferring to a wire rack to cool completely before decorating.

Make the Frosting

Using an electric stand or handheld mixer, beat the butter, powdered sugar, cream, and vanilla together until smooth and stiff peaks form.
Transfer approximately 1½ cups of frosting to a separate bowl and mix in a few drops of black gel food coloring.
Add 6–8 drops of neon green gel food coloring to the remaining frosting and mix until evenly colored.
Fit a large piping bag with a star tip and place it inside a tall glass, folding the top of the bag over the rim. Spoon approximately 1 cup of green frosting down one side of the bag and 1 cup of black frosting down the other side. Set aside.

Decorate the Cupcakes

Combine the green and black sprinkle mixes in a medium bowl. Set aside.
Using a medium ice cream scoop, place a generous scoop of green frosting onto each cooled cupcake. Smooth the frosting into a thick, flat disk using an offset spatula.
Press the frosted tops into the combined Halloween sprinkles until completely coated.
Add a swirl of the black and green frosting onto the sprinkles layer. Drizzle green sparkle decorating gel around the swirl to create a dripping slime effect.
Pipe a further tall swirl of frosting on top and add more green sparkle gel.
Place a green gumball on top of each cupcake. Serve, and Happy Halloween!

Notes

Tips

Gel food coloring works best for achieving a vibrant green cake without adding too much extra liquid to the batter.
Make sure the cupcakes are completely cool before decorating, or the buttercream may melt.
For the two-tone frosting effect, place the green and black buttercream on opposite sides of the piping bag.
The gumballs are decorative and should be removed before serving to young children because they pose a choking hazard.

Substitutions

If French vanilla cake mix is unavailable, you can use regular vanilla cake mix, though the flavor may differ.
Use any Halloween-themed green-and-black sprinkles you can find.
Green sparkle decorating gel is ideal for the slime effect, but other edible green decorating gels may also work.

Storage

Decorate these cupcakes shortly before serving to keep the sprinkles and slime decorations looking their best.
For storage, follow the guidance for your chosen frosting and cake mix, particularly if the cupcakes need refrigeration.

Always consult the Food Standards Agency in your country for the most up-to-date advice on storing and freezing foods: Food Safety (USA) | Food Standards Agency (UK)

Nutrition