Coffee Cake Slice with Coffee Buttercream and Chocolate Curls

Jump to Recipe

This soft, fluffy, moist, buttery Coffee Cake Slice is topped with a smooth and luscious coffee buttercream and finished with fabulous milk chocolate curls. The sponge base is all mixed in one bowl and comes together in minutes. Equally, the easy to make dreamy, creamy buttercream whips up very quickly using store cupboard ingredients. Add these fabulous chocolate curls and tuck in greedily!

I love coffee cake with a cup of tea, but whatever you chose to drink with it, it makes for a perfect treat with morning coffee or afternoon tea and is also delicious for dessert.

How to make Coffee Cake Slice with Coffee Frosting and Chocolate Curls

Collect all your ingredients together and line the baking tin:

In order to guarantee the correct texture of your cake, it is important to use the correct size tin – in this case it is a 20cm/8inch square tin. If your tin is larger, the depth of your cake batter will be less and the cake will cook more quickly. Equally, if the tin is smaller, your cake batter will be deeper and cook more slowly.

1. Sit the tin on greaseproof paper making sure the paper is large enough to line the tin, come up the sides and have a little overhang.
2. Cut out the corners of the paper so it will fit easily into the tin
3. Fold the paper from corner to corner so the size of the centre of the paper matches the base of the tin. Slot inside the tin.

• 

• 

• 

For the coffee cake slice –

• instant coffee mixed with boiling water
• unsalted butter, at room temperature
• caster sugar
• eggs
• plain/all-purpose flour
• cornflour/cornstarch
• baking powder
• bicarbonate of/baking soda
• vanilla extract
• fine salt
• sour cream (or natural yoghurt)

For the coffee buttercream icing –

• instant coffee mixed with boiling water
• unsalted butter, at room temperature
• fine salt, to taste
• icing sugar, sieved

First make this fabulous slice:

1. Dissolve the coffee powder in the boiling water and set aside to cool.
2. It is important that the butter is at room temperature and soft enough to beat. If it is a little hard, beat it with a whisk before adding the other ingredients. If it is already quite soft, you do not need to do this. For information on softening butter, see here.
3. Measure all the remaining ingredients, apart from the coffee, into the mixing bowl with the butter. I place my mixing bowl on top my scales and weigh everything in directly. Add the coffee at the end, when it has cooled a little.
4. Use an electric whisk to beat until combined. This should take less than a minute. Half way, use a spatula to scrape the sides of the bowl and ensure even mixing.
5. Tip into your lined baking tin and level the surface, ensuring the cake goes into all the corners.
6. Bake in the centre of a preheated oven for 45 – 50 minutes until cooked. It is cooked when:
   • the centre feels springy when lightly touched with your finger and no imprint remains.
   • a toothpick inserted into the centre of the cake comes out clean.
   • the cake is beginning to come away from the sides of the tin.
7. Leave to cool in the tin for 5 minutes and then, using the greaseproof paper over-hang, transfer to a cooling rack and set aside until completely cool.

• 

• 

• 

• 

• 

• 

Make the buttercream frosting whilst the cake cools:

1. Mix the coffee with the boiling water and set aside to cool.
2. It is important that the butter is at room temperature and soft enough to beat. For information on softening butter, see here. Add the salt to the butter and whisk until light and fluffy.
3. Put the mixing bowl on the scales, balance the sieve on the bowl and zero the scales. Weigh in half the icing sugar and sieve. Quickly fold in with a spoon. (This is to stop the icing sugar clouding up and making a mess of the kitchen!) Whisk until light and fluffy.
4. Repeat with the remaining icing sugar and whisk again.
5. Thoroughly mix ¾ of the cold coffee into the frosting. Taste to see if you want to add the remaining coffee or any more salt.
6. Cover the top of the cake with the buttercream and make a swirly pattern with a knife or the back of a spoon.
7. If using, make milk chocolate curls using a potato peeler – to get these fabulous curls, the chocolate should be at room temperature, not too cold. If it is cold, and you will get much smaller curls but they will still be pretty.  
8. Serve the cake as is or decorate with chocolate curls or sprinkles.

• 

• 

• 

• 

• 

• 

Made this recipe?

If you make this recipe, do please tag me on instagram @daffodil_kitchen. You could also leave a comment in the box directly below the recipe.