18th Birthday Cake Idea

Last Updated on May 30, 2021 by Amanda P. Brown

18th birthday is an entry into the adult world. It’s all about having fun, freedom, and dreaming big. But with space, this age brings dignity and responsibility. One’s sweet childhood is over, and totally a new world is welcoming him/her. Whenever you are willing to bake a cake for someone who will step in 18, you have to keep all those things in mind.

As it’s a new journey, so the cake should be unique and mainly related to this beautiful entrance. Here are my 3-most favorite 18th birthday cake ideas, which will leave you to say, Wow! That’s amazing.

3-Popular 18th Birthday Cake Idea

1. Black Velvet Cake 

2. Amazing Maltesers Cake

3. Pink Lemonade Brushstroke Cake

1. Black Velvet Cake 

Black Velvet Cake

Black velvet is a fluffy and light cake, having a velvety and rich texture. This cake is regarded as the best birthday cake for girls 18th birthday. It is covered in black buttercream, which gives it a unique flavor, different from other chocolate cakes. Each layer is smothered and moist.

Ingredients (for Serving 12 People)

  • Butter: 400g ( chopped at room temperature)
  • Eggs: 6-piece
  • Plain Flour: 3-cups
  • Caster Sugar: 3-cups
  • Dark Cocoa Powder: 1 ½-cups
  • Vanilla Extract: 1-tablespoon
  • Self-raising Flour: 1-cup
  • Black Food Coloring: 2-teaspoons
  • Bicarbonate of Soda: 2-teaspoons
  • Buttermilk: 2-cups
  • Activated Charcoal Powder: ¼-cup
  • Red Sprinkles (to decorate)

For Red Buttercream

  • Butter: 250g (chopped at room temperature)
  • Red Food Coloring (to tint)
  • Icing Sugar Mixture: 2 ¼-cups ( sifted)
  • White Chocolate: 180g (melted and cooled)

For Black Buttercream

  • Butter: 250g (chopped at room temperature)
  • Dark Chocolate: 200g (melted and cooled)
  • Activated Charcoal Powder: 2-tablespoons
  • Icing Sugar Mixture: 2 ¼-cups (sifted)
  • Dark Cocoa Powder: 2-tablespoons
  • Black Food Coloring (to tint)

Baking Process

1. Heat the fan-forced oven to 180/160c first. Now grease 2 round cake pans (20cm) and line the pan’s bottoms with baking papers.

2. Beat the sugar and butter (using electric beaters) in a bowl until it becomes fluffy and light.

3. Add the eggs with the mixture one at a time, and after beating it well, add another one repeatedly. After that, mix vanilla and food coloring, then mix it well.

4. Mix the flours, charcoal powder, bicarbonate, and cocoa powder into a large bowl. Fold the flour mixture by using a metal spoon into the butter mixture in batches. Alternate each folding with the buttermilk and divide straightway between cake pans.

5. Bake it for 1-¼ hour and cool the pans 10 minutes before taking it out onto the wire racks to cool it completely.

6. Beat butter in a large bowl for red buttercream until it becomes pale using electric beaters. Add the chocolate and half icing sugar gradually in the beating and beat it until it is combined. Slowly mix another half-icing sugar with the red food coloring.

7. Keep ¾-cup buttercream in a separate bowl for decorating purposes and set aside the remaining buttercream.

8. Beat butter (using electric beaters) in a large bowl for red buttercream until it becomes pale. Add the chocolate and half icing sugar gradually in the beating and beat it until combined. Slowly mix another half icing sugar-color icing with black food coloring.

9. Keep ¾-cup buttercream in a separate bowl for decorating purposes and set aside the remaining buttercream. The color will look gray at first but will darken soon.

10. To assemble, use a jagged knife to cut down on the tops from the cakes to even. Trim each cake half-horizontally and place and keep one piece onto a plate. Then stretch one-third of the remaining red buttercream over the cake. Do this two times repeatedly with cake and red buttercream. Place the final cake on top and raise the base piece for the last top cake to become crumb-free and smooth.

11. Spread the black buttercream over the cake thinly to make a crumb layer. Do it carefully between each layer to cover any read buttercream that may be fallen out. Put it in the fridge for 15-20 minutes. Extend another layer of black buttercream over the cake.

12. Take the reserved red and black buttercream into a piping bag fitted with a 1.5 cm ridged nozzle. The pipe revolves around the outer side of the cake.

13. Design red sprinkles along the bottom side of the cake.

2. Amazing Maltesers Cake

Amazing Maltesers Cake

It’s a delicious chocolate cake covered (on the top) with Malteser chocolates. This fabulous 4-layer chocolate cake is something exceptional than the regular 18th birthday cake idea.

Ingredients (for Serving 12 People)

  • Brown Sugar: 1-cup
  • Eggs: 3-piece (lightly whisked)
  • Milk: ¾-cup
  • Self-raising Flour: ¾-cup
  • Butter: 125g (chopped)
  • Plain Flour: ½-cup
  • Malted Milk Powder: ¾-cup
  • Butter: 185g (at room temperature)
  • Milk: 1-tablespoon
  • Plain Flour: ½-cup
  • Icing sugar mixture: 2 ¼-cups
  • Maltesers: 465g


  • Cocoa powder: ½-up
  • Dark cooking chocolate: 300g (chopped)
  • Butter: 30g
  • Thickened cream: ½-cup

Baking Process

1. Heat a 20cm round cake pan with butter in the oven at 160C. Then, wrap the base and side with baking paper.

2. Keep the milk, butter, and brown sugar in a bowl and cook in the microwave on high for 4 to 5 minutes. Stir the mixture every minute so that the butter melts and the blend gets smooth.

3. Combine the flour and cocoa powder with a balloon whisk into the butter mixture. Whisk in the egg and engulf it into the pre-prepared pan. Bake it for about 55 minutes, or you can bake it till a toothpick comes out completely clean from the cake. Allow the pan to cool for 5-minutes before shifting it to a wire rack to chill thoroughly.

4. Now, for making the ganache, take the butter, cream, and chocolate in a bowl. Then cook ganache for 2 to 3 minutes on high in the microwave. Stir the mixture every minute so that the chocolate melts and the blend gets smooth.

5. Beat the extra butter (using an electric beater) in a bowl until it gets creamy and pale. Add the extra milk, malted milk powder, and icing sugar, and beat until creamy. Then, beat ganache of 1 ½-tablespoon.

6. Set aside the remaining ganache for 1 hour 30 minutes. In the meantime, cut the cake horizontally into 4-layers with a sharp knife. Set the cake foundation on a serving platter. 

7. Expand over 1/3-of the icing. Do continue layering with the remaining icing and cake, finishing with cake. Cover and place in the fridge, then chill for 1 hour and 30 minutes

8. Tract the ganache over the top and edge of the cake. Set out with Maltesers.

3. Pink Lemonade Brushstroke Cake

Pink Lemonade Brushstroke Cake

It’s a blushing pink cake in which you can bring out an artistic side. This cake looks so beautiful for the pastel-colored brushstrokes, and it can be the best idea for an 18th birthday cake for girls.

Ingredients (for Serving 20 People)

  • Butter: 375g (unsalted ,at room temperature)
  • Pink Lemonade: 1-cup
  • Caster Sugar: 1 ½-cups
  • Grenadine: 2-tablespoons
  • Vanilla Extract: 2-teaspoons
  • Eggs: 5-piece ( at room temperature)
  • Self-raising Flour: 3 ¾-cups
  • Wilton Orange Candy Melts: 75g
  • Wilton Bright White Candy Melts: 225g

Pink Swiss Meringue Buttercream

  • Butter: 400g (chopped, at room temperature)
  • Caster sugar: 1-cup
  • Grenadine: 2-teaspoons
  • Egg Whites: 4-piece

Baking Process

1. Heat the oven (fan-forced) to 180/160C. Line the side and base of (around 22cm and approximately 18cm) 2 cake pans.

2. Beat the sugar, butter, and vanilla in a bowl using electric beaters until it becomes creamy and pale. Take one egg at a time, beating thoroughly after each addition, then add the next one. Fold in lemonade, Flour, and grenadine by using a large metal spoon until it gets well combined. Divide it between the prepared two pans. Smooth the surface of each pan.

3. Keep both cakes in the oven and bake it for 45 minutes for the small cake and 55 minutes for the large cake or until a skewer entered into the center comes clean. Keep it aside to cool thoroughly.

4. Take 3-small bowls. Keep 150g white candy melts in one bowl. Take remaining white candy melts and orange candy melts in another bowl and takes pink candy melts in the third bowl.

5. Heat the melts on medium heat, stirring every minute until it melted, and line 2 trays with the baking papers. Brush the lined baking tray with a pastry brush and paint to create a brushstroke effect. Similarly, use the remaining bowls of melts to make different colors of brushstrokes. Set aside to set for 15 minutes.

6. Combine sugar and egg whites in a bowl for buttercream. Place it over a saucepan of water below the boiling point. Then, stir it for 8 to 10 minutes by using a balloon whisk. Separate it into a clean bowl. Beat it for 5 minutes. Gradually add butter and beat it well. When the mixture is smooth, add grenadine and beat it to combine.

7. Cut down the cakes in half horizontally by using a jagged knife. Place a large layer of cake on a plate. Cover with a bit of amount of buttercream. Continue layering by adding a large cake layer, buttercream, and tiny cake layers. Stretch half of the remaining buttercream over the side and top of the cake. Cool it for 15 minutes in the refrigerator.

8. Now, distribute another half of the remaining buttercream over the side and top of the cake. Set out top with a fresh flower and one side of cake with brushstrokes.

What Do You Write on an 18th Birthday Cake?

If you are writing on a birthday cake for somebody turning 18, here are some suggestions:

  • It’s showtime!
  • Happy adulthood! 
  • Be adventurous
  • Happy 18th!
  • Happy 18th bday!

Why Is the 18th Birthday Special?

When a person attains the age of 18, he or she ends to be a child. He/she entered into adulthood capable of making responsible choices and gained the legal right to vote and drink in a pub. People usually throw an especial dinner party to celebrate their entry into full adulthood. Additionally, this birthday is also significant in various cultures yet.

What Things Did People Use to Do on Their 18th Birthday?

On the 18th birthday most of the boys and girls like to do the following things: 

  • Go to a movie with friends
  • Go for dinner with family or friends
  • Go on a 2-3 days trip
  • Throw a birthday party 
  • Take professional photos to create a memory 
  • Go to a concert, shopping or amusement park

Final Verdict

My given 18th birthday cake ideas (mentioned above) are best to celebrate the 18th birthday. These birthday cake designs are also simple, sophisticated as well. You can bake any of them for all the teens entering adulthood. These birthday cake ideas are simple to bake and perfect to surprise your daughter, relatives, or even friends and enlighten their birthday celebration. 

You May Also Like To Read:

  1. 16th Birthday Cake Idea
  2. 10-Popular Baby Girls 1st Birthday Cake
  3. 12-Easy 1st Birthday Food Ideas

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