Gralke, here you go. The Orchard icing is one that comes already made in a box that you just roll out and use. You may have one similar where you are, but if not just make some yourself.
VANILLA SLICE2 sheets puff pastry
½ cup caster sugar
½ cup custard powder
600ml milk
1 tsp vanilla extract
1 tblsp gelatine
1/3 cup hot water
300ml thickened cream
Icing½ pkt Orchard white icing
dessicated coconut to sprinkle on top
alternative1 ½ cups pure icing sugar
1/3 cup passionfruit pulp
1 tblsp melted butter
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Place thawed pastry on baking paper lined trays, prick well and bake in very hot oven 5-10 mins or until puffed and golden. Remove from the oven and with a pair of clean oven mits, press down genlty on the pastry to flatten. While still warm, trim pastry to fit a 23cm square tin that has been lined with alfoil to aid removal of the slice when finished. Make sure there's enough foil hanging out to be able to pick it up with.
Blend custard powder and sugar with sufficient milk to form a smooth paste, add remaining milk, mix, then pour into a medium saucepan. Cook over low heat, stirring constantly until mixture boils and thickens. Cook for 1 min more. Remove from heat.
Sprinkle gelatine onto nearly boiling water, stir briskly until dissolved then stir into custard. Place a piece of plastic wrap over surface of custard, this will prevent a skin forming. Allow to cool to room temp, then add vanilla. Gradually add cream, beating at high speed until well blended.
Place 1 piece of pastry, smooth side down into the base of tin. Pour custard mix carefully over the pastry, top with remaining pastry, smooth side up. Press down firmly. Set aside whilst preparing the icing.
If using Orchard icing. Follow pack intructions (very easy). Cut out to fit top of pastry, press down gently, sprinkle with coconut, then cover the top of the tin with wrap and place in fridge to set for about 6 hours. Gently cut into squares.
Passionfruit icing:Combine all 3 ingredients until smooth. Spread over top of pastry and chill in the same way. Cut into squares.