Three cherry Swiss roll trifle

Method

1. Preheat the oven to 200°C. Line a Swiss roll tin or baking tray with good-quality baking parchment.
2. Combine the flour, baking powder and salt in a bowl and set aside. Then in another bowl or in your stand mixer, beat together the bananas, lemon juice and sugar, then beat in the vanilla paste and olive oil. The mixture should be fluffy.
3. Gradually fold the flour mixture and the water into the creamed banana mixture, then pour into the lined tin and spread it flat with a palette knife. Bake in the oven for 10–12 minutes or until the top is springy to the touch.
4. Remove it from the oven and clear a space on your worktop to do the next very important stage of making a Swiss roll. Sprinkle the 2 tablespoons caster sugar over the sponge while it is still hot. Put another sheet of baking parchment over the sponge and, grabbing each side of the still-hot tin with your oven gloves, flip it over quickly. Remove the tin and leave the sponge to cool for 5 minutes, still covered on both sides with baking parchment.
5. For the filling, in a bowl or stand mixer, beat the vegan margarine with the icing sugar, then add the sour cherries. Combine until you have a fluffy pink cream.
6. Remove the top sheet of baking parchment from the fairly cool sponge. Spread the filling, using a rubber spatula or a palette knife, over the sponge. Then, starting from the short end and using the bottom layer of parchment to aid you, carefully roll up the sponge and cream layer into a roulade shape. Imagine you are rolling sushi! Still in its parchment, wrap the Swiss roll tightly in clingfilm and chill in the fridge until ready to use.
7. To make the jelly, put all the ingredients in a medium saucepan and bring to the boil. Simmer for 5 minutes, then take off the heat and let it cool. It’s important not to use too much agar agar powder or it will set too hard and have an unpleasant mouthfeel; better to have slightly less than more, and every brand has its own strength, so it’s hard to see until it sets whether it has gelled or not.
8. To assemble, remove the Swiss roll from the fridge and take off the clingfilm. Using a sharp knife, slice the roll into 1.5 cm slices. Line the bottom and the sides of a glass dish with the slices. Then fill the bottom with a layer of morello or black cherries. Pour in the cooled jelly to cover the cake and cherries, leaving space on top for the cream, and put it in the fridge to set (you may not need all the jelly, depending on the size of your trifle dish).
9. Once the jelly has set, either squirt or pipe thick vegan cream onto the jelly, dotting it around the edge and the centre. Add the fresh cherries, stems up. Dust with icing sugar and serve.