Skip to content

How to bake a 1-hour chocolate birthday cake

A showstopping birthday cake ready in an hour? Yes, it can be done! If you're new to baking or just short on time but want to make something special for your friend or family's birthday, this is the recipe for you. With a fluffy all-in-one chocolate sponge, creamy chocolate icing and simple decoration, this is your new go-to cake recipe. Check out the flavour spins to make it different every time and don't forget to screenshot the ingredients list at the bottom before you go shopping.

  1. Prep the tins

    Preheat the oven to gas 4, 180°C, fan 160°C. Grease and line 2 x 20cm round cake tins.

    Prep the tins
  2. Beat together the cake mixture

    Mix the cocoa powder with 125ml hot water into a paste in a large bowl. Add all the remaining cake ingredients. Beat with an electric hand whisk until creamy, smooth and fully combined.

    Beat together the cake mixture
  3. Bake

    Divide the mix between the two tins. Tap each on a work surface (this will prevent air-bubbles). Bake for 30 mins until risen and an inserted skewer comes out clean. Remove from the tins and leave to cool completely on a wire rack. 

  4. Make the icing

    Meanwhile, make the icing. Put the butter, icing sugar, cocoa powder and yogurt into a food processor and pulse until blended. Add the melted chocolate and blitz until smooth.

    Make the icing
  5. Spread the icing

    To decorate, level the top of the cakes if necessary. Place onto a cake board or serving plate, then spread over one third of the frosting. Place the second cake on top. Spread over another third of the frosting.

    Spread the icing
  6. Add icing decoration

    Fill a disposable icing bag with the remaining frosting. Snip a ½ cm-1cm hole from the end and squeeze peaked rounds all around the edge of the cake.

    Add icing decoration
  7. Decorate

    Scatter the sprinkles over the rounds, then top each one with a Smartie. Fill the centre with candles.

  8. Flavour spins

    Once you've tried the classic double chocolate, try these flavour spins on this simple recipe to find your favourite flavour: 

    Chocolate orange

    Add the zest of 3 oranges to the bowl in step 2. Replace the dark chocolate in the frosting to a good quality dark orange chocolate. Decorate with orange zest.

    Zesty lemon

    Replace the cocoa powder paste mix with 50ml lemon juice and add the zest of two lemons to the bowl in step 2. Reduce the baking powder to ½ tsp. Replace the chocolate frosting with lemon buttercream made with 190g softened butter mixed with 380g icing sugar and 1 tbsp lemon juice. Decorate with lemon zest.


    Replace the cocoa powder paste mix with 50ml strong coffee (made with 1tbsp instant coffee granules mixed with 50ml boiling water, cooled). Reduce the baking powder to ½ tsp. Dust with cocoa powder to decorate.

  9. Ingredients

    Screenshot this ingredients list before you go shopping for everything you need to make this special chocolate cake:

    75g cocoa powder
    250g softened butter, plus extra for greasing
    250g golden caster sugar
    275g self-raising flour
    1¼ tsp baking powder
    4 eggs
    1 tsp vanilla extract

    For the frosting
    200g butter, softened
    200g icing sugar
    5 tbsp cocoa powder
    3 tbsp plain yogurt
    90g dark chocolate, melted and cooled slightly

    For decorating
    3 tsp bright sprinkles
    Small handful Smarties

    Serves 14

    Each serving contains

    • Energy

    • Fat

      34g 49%
    • Saturates

      20g 98%
    • Sugars

      39g 43%
    • Salt

      0.3g 6%

    of the reference intake
    Carbohydrate 57.9g Protein 6.5g Fibre 0.9g