Method

Place the strawberries, caster sugar and 80ml water in a heatproof bowl. Place bowl over a saucepan of gently simmering water. (The bowl should not touch the water).
Stir to combine then cover the bowl with foil and cook for about 30 minutes until the strawberries soften. Add the rhubarb, cover and cook for a further 30 minutes until the rhubarb is tender. Remove from the heat.
Place a little cold water in a small ramekin. Sprinkle over the powdered gelatin – it will form a sponge. Place the ramekin in a saucepan with a little gently simmering water. Allow the gelatin to become liquid but before careful not to let it get too hot. Carefully remove the ramekin from the simmering water. Pour the liquid gelatin into the strawberry and rhubarb and stir to combine. Leave to cool and begin to set.
Arrange half of the sponge squares in the glass bowl and drizzle with half of the alcohol. Spoon over half of the strawberry mixture. Repeat once more. Pour the custard over the trifle. Cover the bowl and chill for about 1 hour or until ready to decorate and serve.
To decorate – stir the vanilla extract through the whipped cream and spread over the trifle. Decorate with strawberries and mint leaves. Dust with icing sugar, if wished.