GBBO Recipe Challenge With Stephanie Forster (Illusion Cake Special)

by Owen Redford

GBBO Recipe Challenge With Stephanie Forster (Illusion Cake Special)

Today marks the first edition of our Star Baker profile! Each week, a special guest baker will bake a cake themed from the previous week’s episode of Great British Bake Off. This week we have Stephanie Forster (Owner of Your CakeBox) who takes on the illusion cake challenge with her anti-gravity prosecco cake recipe.


Name: Stephanie Forster

Occupation: Owner of Your CakeBox

Social Media: Website, Facebook, Twitter & Instagram    

  1. How did you get into baking?

My nan is a very good baker, who would always bring cakes to family get-togethers and parties. I’ve always loved baking, but it was only after creating a showstopper for a party a few years ago and receiving great feedback that I decided to take it more seriously.

  1. How long did the cake take from start to finish?

This particular cake took me just over 5 hours. I tend to pay attention to the small details, so this can take me longer than expected once I’m on a roll!

  1. What’s your favourite thing about the cake?

The Prosecco buttercream! It’s a nice surprise when you tuck into the cake and it’s always good to know that the extra Prosecco from the bottle will keep you on track throughout the bake!

  1. What was the hardest thing about making the cake?

It’s always tricky when using new equipment, and this was my first cake trialling the Anti-Gravity Cake Stand. I find YouTube is great for cake hacks and baking secrets to improve your skills.


Vanilla sponge with Prosecco Frosting, Anti-Gravity Prosecco Cake (Serves 12 people)




Anti-Gravity Cake Stand

Hand/Standing Mixer

1-2 Bowls for mixing


Thin Metal Spatula


Plastic/Metal Side Scraper

Icing Smoother(s)

Fondant Acetate Sheets

Sugar Syrup:

130g Caster Sugar

230ml Water

  • Just bring 1 cup of sugar and 1 cup of water to a boil, remove from heat and let cool (remember, be careful - sugar gets much hotter than water alone). You can add any flavourings or liqueurs you would like at this point. Set-aside until later.

Prosecco Buttercream Frosting:

250g Unsalted butter

500g Icing sugar

200ml bottle of Prosecco

2 tsp. Vanilla essence

  • After following the below method and the cake is in the oven, mix up the buttercream; add the buttr at room temperature to your mixer and slowly add the sieved icing sugar. Once fully combined, light and fluffy, add the half of the contents of the Prosecco and vanilla essence.
  • The other 100ml of Prosecco is for you to drink whilst baking – it makes everything so much better!


250g Stork Margarine

250g Caster Sugar

250g of Self-Raising Flour

85g of Plain Flour

2 tsp Baking Powder

½ tsp Salt

5 Eggs

90ml Semi-Skimmed Milk

2 tsp Vanilla Essence


  1. Preheat your fan oven to 190 degrees Celsius.
  1. Line an 8” round, 3” deep tin with margarine and add baking paper to the bottom of the cake tin.
  1. Mix together the margarine and sugar using a standing or handheld mixer until fluffy and light. Make sure to use a spatula to scrape down the sides part way through.
  1. Sift the dry ingredients into a separate bowl and add a few tablespoons at a time to the butter mixture whilst adding an egg at a time too. This makes sure the cake mixture doesn’t split.
  1. Once fully combined, add the milk and the vanilla essence. Add more vanilla to taste if you desire.
  1. Add the mixture to the cake tin and place in the middle of the oven for 70-80 minutes. TIP: Do not open the oven until 2/3 of the way through the bake to prevent the cake from sinking. Make sure to test the cake with a skewer to make sure it is cooked all the way through before removing from the oven.
  1. Once the cake is fully baked, remove from the oven and let it cool.
  1. Preferably chill overnight, covered in a clean tea towel or to speed things up, place the partially cooled cake on a wire rack or cake board and place in the fridge for 30-45 minutes.
  1. Once the cake is nice and cool, remove from the fridge and cut the cake in half horizontally to end up with 2 equally sized layers. Using a squeezy bottle add a moderate layer of the sugar syrup to both the top and bottom layers to keep the cake moist.
  1. Then add half of the buttercream roughly 1 inch thick to the bottom layer with a thin metal cake spatula.
  1. Place the top half of the cake on top and add a thin layer of the remaining buttercream to the top and sides of the cake. This is the crumb coat, so it doesn’t matter if you make a mess or see the cake through the buttercream at this stage.
  1. Place back into the fridge for at least 20 minutes to fully harden the buttercream ready for another layer of the buttercream.
  1. Ensure this layer is around 2-3cm thick all over to start with, and whilst using a turntable and a plastic or metal side scraper, remove the excess to leave nice sharp edges.
  1. Refrigerate again for a further 20-30 minutes until firm.
  1. Roll out your desired colour fondant and either using your hands or a large rolling pin, after slightly wetting the buttercream, place the icing over the cake and smooth down the top and edges with a cake smoother.
  1. TIP: To get the perfect sharp edge, use acetate sheets. Keep one sheet on the side of the cake (that sticks up past the top of the cake) and one on the top of the cake – the one on the top butts up against the one on the side and using firm pressure, slide the two round the cake together, making sure to keep them together. This action squeezes the fondant into the right angle you are creating with the acetate and forms that sharp edge. Just be careful to avoid digging the corners of the acetate into the fondant.
  1. Put together your Anti-Gravity Cake Stand and whilst keeping the cake straight and level, push the cake down onto the middle rod until it’s sitting on the base. Make sure it’s level! You can now add the droplet decorations in white fondant icing down the centre rod of the cake stand. Make sure it is covered completely.
  1. Add the mini Prosecco bottle onto the angled connecting rod and cover any remaining parts of the stand with icing.
  1. Use petal dust or shimmer edible paints to create depth and shadows on the droplets.
  1. You may need to leave the icing to set firm to make sure none of the droplets fall off when working on the rest of the decorations.
  1. Add 2-3 strips of coloured icing around the edge of the cake in your desired colour and add roses to finish.
  1. Tuck in, and enjoy!


Thanks for reading and check back next week for our second GBBO recipe challenge. For more information on Stephanie and Your Cake Box, check out their Website and follow them on Facebook, Twitter & Instagram!    

Happy baking!