Line your cupcake tin with cupcake cases then set it aside. Preheat the oven to 180C/350F whilst preparing the biscuit base.

In a mixing bowl, crush the biscuits into crumbs. Add in the melted butter and mix to combine. Place a heaped tablespoon of this mixture into each of the cupcake cases and press down to form a firm base. Bake the bases in the hot oven for 5 minutes. This firms up the crust and stops it being so crumbly, but also helps it not absorb moisture from the cake mixture.

In a large bowl, beat the butter until really soft and smooth. Add in the sugar and beat together until completely combined and slightly paler.

Sift the flour, baking powder, bicarbonate of soda, and salt into the same bowl and beat it all together until the mixture resembles damp sand.

Tip in the eggs, yogurt and vanilla into the jug. Mix well until smooth and totally combined.

Tip in ¾ of the wet mixture into the dry mix and beat to combine thoroughly. Scrape the bowl down, then add in the remaining wet mix to the batter and beat again until mixed. Add in the mashed banana and beat to combine. Finally, turn the speed to high and beat for 30 seconds. The cupcake batter should be totally smooth and wonderfully light and creamy.

Spoon or scoop the cupcake mixture evenly between the 12 cases, then bake in the preheated oven for 20-24 minutes until springy to touch and a skewer or toothpick inserted into a cupcake comes out clean. Cool for a few minutes in the tin, then remove to a cooling rack and cool completely.

To make the caramel buttercream, first beat the butter for 3-4 minutes until really soft and spreadable, and paler in colour. This is really important as it gives a really light buttercream that is just heavenly and fluffy. I would hightly recommend not skipping this step!

Add in half the icing sugar and mix in slowly until completely combined, then do the same for the remaining sugar. Scrape the bowl down, then add in 60g/3tbsp caramel and beat it all together until smooth. Turn the mixer on high, and mix the buttercream for about 2 minutes until pale, fluffy and cloud like.

Using a spatula, vigourously mix the buttercream around the mixing bowl for about a minute or so. This smooths out the buttercream, pushing out air bubbles, so resulting in a really silky buttercream to work with for the final steps.

Transfer the buttercream to a piping bag fitted with a 1M piping nozzle. I find it easiest to place my piping bag into a glass to help me hold the bag open, so I can use both my hands to hold my mixing bowl and steady the piping bag as I fill it. Once you have filled the bag, twist the top of it to stop the buttercream from escaping out that way. Set the piping aside whilst preparing the cupcakes for filling and icing.

Using a corer or a knife, hollow out the middle of each cupcake then eat the pieces of cake removed. This is purely for quality testing, so obligatory to ensure every cupcake is good! Fill each hollowed out cupcake with some of the leftover caramel all the way to the top. Be generous, this stuff is good!

Pipe a swirl buttercream over the top of each cupcake, covering the hidden caramel middle. Remember to keep the pressure steady and the bag upright as you move it around the cupcake. Top each buttercream flourish with a drizzle of extra caramel and some dark chocolate shavings. Enjoy!