Celebrate Valentine's Day in style with this Hidden Heart Cake, a delicious vanilla sponge loaf cake with a vibrant red heart revelead with every slice, and vanilla icing on top. It's a rich and indulgent Valentine's Day cake that will impress your loved ones, and it's easy to make with a handful of ingredients.

Valentine's Day is a wonderful occasion to show your love to your other half, and a romantic meal is a great way of spoiling them on the big day. I have a delicious menu of appertizers and mains for Valentine's Day and a Valentine's Day dessert menu too to make your prep easy peasy.
And this hidden heart loaf cake is guaranteed to be a smashing success. It's such an impressive cake to slice into, the vibrant red heart is a lovely surprise that will delight everyone.
The slice of cake reminds me of an envelope with a red heart on it, perhaps a love letter from an admirer or your loved one?
The sponge cake is adapted from a basic pound cake recipe, which I also tweaked for my Victoria Sponge Cake. It's basically a cake made with equal amounts of flour, butter and sugar plus eggs.
Now, you know me, I like to cut down on the amount of sugar used, so my cake has 50 g less sugar than required, but that doesn't affect the taste of consistency of the sponge, so feel free to play around with the amount of sugar.
If you happen to have any leftover cake, why not make these delicious Valentine's Day Heart-Shaped Cake Pops? They are so yummy!
Jump to:
Note!
Go to the recipe card at the bottom of the post for exact quantities and detailed instructions!
Ingredients used for the sponge

- butter - it has to be soft, but not melted, if it's a warm day I usually leave the butter out on the kitchen counter to soften, otherwise I tend to place it in the oven at a very low temperature for a few minutes until I am happy with the texture
- flour - I used self-raising flour, but plain flour can be used too as long as you add the baking powder
- sugar - I used granulated sugar, but caster sugar works as well
- baking powder - I add a teaspoon even if I use self-raising flour, we need the cake the be well risen to cover the hearts
- vanilla extract - or any other extract of your choice
- red food colouring - I highly recommend using a paste food colouring rather than liquid, the liquid is never strong enough for a vibrant colour, and most of the times you end up with a sad brownish not vibrant red
Step-by-step photos and instructions for making the vanilla sponge
- add the sugar and butter to a large mixing bowl, and use a hand mixer to beat them well until you get a light-coloured paste
- add the eggs one by one mixing well after every egg
- sift in the flour, add the baking powder and vanilla extract, and use a spatulla to mix everything into a batter

- transfer a quarter of the batter to a different mixing bowl, add the red food colouring, and mix well to have a smooth uniform batter
- line a square baking tray ( mine is 20 cm, 8 inches in diameter) with non-stick paper, and add the batter in one even layer
- bake in the preheated oven at 180 degrees Celsius ( 350 Fahrenheit) for 20 minutes
- remove it from the oven and leave it to cool down completely
- use a heart-shaped cookie cutter to cut out hearts from the sponge

- add a few tablespoon of the vanilla batter to a loaf tin that has been greased and floured, making sure it's in an even layer
- arrange the red hearts on top of the batter, then use the remaining batter to colour the hearts completely
- bake for 50 minutes until a toothpick inserted in the middle comes out clean
- leave it too cool down completley before glazing

Ingredients used to make the vanilla icing

- icing sugar - confectioner's sugar, make sure it's well sifted or the icing will be lumpy
- milk - for loosening the icing
- vanilla extract - for extra flavour
Step-by-step photos and instructions for making the glaze
- sift the icing sugar in a mixing bowl, add the vanilla extract and milk
- mix well until you get a smooth, runny glaze
- pour the glaze over the cake, then top with red sponge crumbs
- allow the glaze to set before slicing the cake

Expert tips
Right, getting the red hearts to stay where they should stay can be a bit tricky, and that's because when the cake rises, it pushes the red hearts up and they can end up at the very top. Still a nice cake, but the hearts won't look as great.
After testing it a few times, I can say that what helps with this issue is cooling the red sponge well, ideally place it in the freezer for 10-15 minutes once cooled.
Then, when the hearts are arranged on top of the thin layer on batter at the bottom of the tin, press down on the hearts well so they are stuck to the batter. In this way, when the sponge rises, the hearts won't shift as much.
Make sure the oven is well preheated when the cake goes in, this is ensure that the cake rises rapidly before the hearts can shuffle around.
It is crucial to have plenty of batter left for covering the hearts, otherwise the top of the hearts will be exposed during baking.

If you’ve liked this recipe or any other recipe on the blog then don’t forget to rate the recipe and let me know how you got on in the comments below, I love hearing from you! You can also FOLLOW ME on FACEBOOK, INSTAGRAM , YOUTUBE, TIK TOK , FLIPBOARD and PINTEREST to see more delicious food and what I’m getting up to.

Valentine's Day Hidden Heart Cake
Ingredients
For the sponge
- 300 g self-raising flour
- 300 g butter, soft
- 250 g granulated sugar
- 1 teaspoon vanilla extract
- ½ teaspoon red food colouring, paste
For the glaze
- 200 g icing sugar ( confectioners' sugar)
- 2 tablespoon milk
- ½ teaspoon vanilla extract
For decorating
- 1 tablespoon red sponge crumbs ( or sprinkles)
Instructions
- Preheat the oven to 180 degrees Celsius ( 350 Fahrenheit).
- To make the sponge, add the soften butter and sugar to a large mixing bowl.
- Use a hand mixer to beat them well until creamy.
- Add the eggs one by one, beating well after every egg added.
- Sift in the flour, add the baking powder and vanilla extract, and use a spatula to mix everything well into a batter.
- Transfer a quarter of the batter to a different mixing bowl, add the red food colouring, and mix well to get a smooth red batter.
- Line a square baking tray ( mine is 20 cm, 8 inches in diameter) and add the red batter to it in one even layer.
- Bake for 20 minutes, then remove the sponge from the oven, and leave it to cool down completely.
- Freeze it for 10-15 minutes once it's cool.
- Use a heart-shaped cookie cutter to cut out hearts from the red sponge.
- Butter and flour a regular loaf tin.
- Add 3 tablespoons of the remaining vanilla batter to the bottom of the tin, making sure it's nice and even.
- Arrange the hearts on top of the batter, pressing down well to make sure the hearts are stuck into the batter.
- Cover the hearts with the rest of the batter.
- Bake at 170 degrees Celsius (340 Fahrenheit) for 50 minutes, or until a skewer inserted in the middle of the cake comes out clean.
- Remove the cake from the oven and leave it to cool down completely.
- To make the icing, mix the icing sugar, vanilla extract and milk to get a smooth, runny glaze.
- Pour the glaze over the cake, then decorate with crumbs left from the red sponge.
- Allow the glaze to set before slicing the cake.
Video
Notes
- Click on the US Customary at the bottom of the list of ingredients to see the amounts listed in cups and ounces.
- Make sure the oven is well preheated when the cake goes in, this is ensure that the cake rises rapidly before the hearts can shuffle around.
- It is crucial to have plenty of batter left for covering the hearts, otherwise the top of the hearts will be exposed during baking.
Renee says
It IS adorable. Our granddaughters are 6 and 9.
Perfect ages to appreciate such a thing.
Daniela Apostol says
Thank you! Indeed, it'a lovely cake that little ones find very appealing, we all loved it!
Renee says
So, obviously, Noone is freaking out over red food coloring. I figure we won't be eating this every week so.....
I'm going to try this but devote less batter to be turned red and use a smaller cookie cutter.
Maybe there will be more of the plain to rise up and cover the red.
Daniela Apostol says
The amount of food colouring used is very small, plus, compared to all ready-made cakes from supermarkets, it's still much better quality, as the rest of the ingredients are fine.