1.Preheat oven to 200°C (180°C fan forced). Grease oven trays, line with baking paper.
2.Beat butter, sugar and egg in a small bowl with an electric mixer until light and fluffy. Beat in sifted dry ingredients and buttermilk, on low speed, until mixture is smooth.
3.Drop level tablespoons of mixture about 5cm (2 inches) apart onto trays.
4.Bake about 10 minutes. Cool on trays.
5.Meanwhile, make chocolate ganache. Bring cream to the boil in a small saucepan. Remove from heat, add chocolate, stir until smooth.
6.Beat cream in a small bowl with an electric mixer until firm peaks form. Spoon whipped cream into a piping bag fitted with 2cm (¾-inch) fluted tube. Spread jam, then half the chocolate ganache on flat side of half the cooled pies, pipe whipped cream on top. Sandwich with remaining pies.
7.Spread remaining ganache over pies, sprinkle with coconut.
You can use just one 300ml carton of thickened cream for this recipe. Whoopie pies are best eaten the day they are made.Note