The whoopie pie is a classic American treat, made from two soft cake-like cookies, sandwiched together with a sweet, creamy centre. Liam’s version is made with red velvet sponge, filled with marshmallow fluff, and then shaped and decorated to look like American footballs.
Preheat oven to 200°C/180°C fan/400°F/Gas 6.
Using the template, draw 12 oval shapes onto the baking parchment lined baking sheets and set aside.
For the whoopie pies, in a stand mixer fitted with a paddle attachment, beat the butter and soft light brown sugar together until pale and fluffy.
In a separate bowl, whisk the egg and vanilla extract together, then gradually add to the butter and sugar, continuing to beat all the time.
In another bowl, sieve together the flour and baking powder, then add to the butter and sugar mixture, in three batches, alternating with the buttermilk.
Stir through the red food colouring and a pinch of salt.
Transfer the mixture to the piping bag with no nozzle, snip 1 cm off the bottom and using the template to help you, pipe 12 oval shapes on each baking tray.
Bake for 10-15 minutes until slightly risen and fluffy, with an even colour. Remove from the oven and leave to cool.
For the marshmallow fluff, in a large heatproof bowl, mix the egg whites, sugar and water together. Microwave the mixture in 30 second intervals, stirring well each time. Check the temperature of the mixture after every 30 seconds and continue to heat until it has reached 65˚C/149°F.
Transfer to a stand mixer fitted with a whisk attachment and whisk on full power until white, fluffy and holds a peak.
Transfer ¼ of the marshmallow fluff to the piping bag fitted with a No. 2 writing nozzle.
Evenly spread the rest of the marshmallow fluff over 12 of the whoopie pies. Sandwich them together with the remaining 12 whoopie pies.
Using the marshmallow fluff in the piping bag, pipe traditional lines and stiches onto the tops of all 12 whoopie pies to look like American footballs, using the picture to guide you.