A twist on the classic fraisier cake, with pistachio and mint to contrast with the sweet strawberries and silky crème mousseline filling. As jelly resembles water, I thought decorative fondant frogs would be the perfect fit. (I use agar agar to make the jelly vegetarian-friendly, but I also like the texture; it slices really neatly.) This dessert takes a little more prep time than usual, to make all the different components, but it brings so much satisfaction when you peel off the acetate to reveal the impressive layers.
For the sponge
50g salted butter
4 medium eggs
125g caster sugar
125g self-raising flour
For the crème mousseline filling
625ml whole milk
2tsp vanilla bean paste
200g caster sugar
6 egg yolks
3tbsp pistachio paste
⅛tsp almond extract
160g cubed, unsalted butter (at room temperature)
Pinch of salt
Green food dye
For the simple syrup
100g caster sugar
25g lemon juice
For the jelly layer
4g agar agar powder
Fresh mint leaves
Edible flowers (optional)
Extra flowers to decorate (use edible flowers, or remove inedible flowers before serving)
Green, black and white fondant (to shape frogs and lily pads)
Heat the oven to 200C (180C fan)/400F/gas mark 6, then grease and line the base of a 23cm (9in) round tin.
First, make the sponge. Melt the butter in a bowl and set aside. Add the eggs and sugar to a bowl and whisk for at least seven minutes, until it is light, fluffy and holds a trail for five seconds. Sift in two-thirds of the flour and gently fold it in. Next, sift in the remaining flour and fold that in. Remove a scoop of batter and fold in with the melted butter in the bowl. Return this to the main mixture and fold until evenly combined.
Pour into the baking tin, spread evenly, then bake for about 25 minutes, until the cake is springy on top. When done, turn out on to a wire rack and leave to cool.
Meanwhile, make the crème mousseline. Add the milk and vanilla to a pan. In a separate bowl, whisk together the caster sugar, egg yolks, pistachio paste, almond extract and cornflour.
Heat the milk and vanilla mixture in the pan until just starting to bubble. Pour a quarter on to the egg mixture, whisking constantly as you pour. Add the rest of the milk gradually until combined, then transfer the mixture to a saucepan, continuing to whisk constantly over a medium heat until very thick. Keep stirring until the mixture no longer appears to be thickening. At this point, add the cubes of butter and a pinch of salt, to taste. Stir until melted and combined. Stir in the green food dye.
Transfer to a shallow dish and cover with clingfilm, then refrigerate until cool.
For the simple syrup, add the sugar, water and lemon juice to a pan and stir intermittently over a high heat until melted. Bring to a boil for one minute, then remove from the heat.
Use a sharp knife to cut the cooled sponge in half horizontally. Place a 23cm entremet ring on a serving plate, then line the inside with a tall sheet of acetate, securing it with tape. Place a layer of cake inside, making sure the acetate fits snugly around it. Brush some of the simple syrup generously over the cake.
De-stem and cut the strawberries in half, then place these around the circumference of the cake – side by side, with the cut side facing the acetate.
Remove the cooled crème mousseline from the fridge, whisk until smooth again, then transfer to a piping bag. Pipe around the strawberries and on to the base of the cake, to create a spiral. Place extra strawberries in the centre, on top of the spiral, then pipe more crème mousseline on top, making it level with the top of the strawberries. Place the second layer of cake on top and brush this with simple syrup. Cover this with a very thin layer of crème mousseline, making sure this goes right up to the edges of the acetate (this will stop the jelly leaking through). Place in the fridge and chill for two hours.
When chilled, make the jelly. Add the water, sugar and agar agar powder to a pan. Stir intermittently over a high heat, until all the sugar and agar agar has dissolved and the mixture comes to a boil. Boil for a minute, then remove from the heat. Leave to cool for 10 minutes or so, until the bubbles have dissipated, then pour on top of the entremet. Push mint leaves and edible petals into the jelly. Leave to set completely at room temperature, or place in the fridge to speed this up.
When completely set, remove the entremet ring and carefully peel off the acetate to reveal the layers. Decorate with fondant lily pads and frogs, plus extra flowers.