Step 1

Preheat oven to 160°C/140°C fan-forced. Line 2 baking trays with baking paper. Using an electric mixer, beat butter, sugar and vanilla until light and fluffy. Sift flour and custard powder over butter mixture. Stir with a wooden spoon until just combined and a soft dough forms.

Step 2

Using 1 heaped teaspoon of dough per ball, make 30 balls. Place on prepared trays, leaving room for spreading. Using a fork dipped in flour, lightly flatten each biscuit until 1cm thick. Bake for 15 to 20 minutes or until light golden. Cool on tray for 10 minutes. Transfer to a wire rack to cool completely.

Step 3

Meanwhile, make raspberry filling: Using a whisk, beat butter in a bowl until light and creamy. Add vanilla. Whisk to combine. Add icing sugar. Whisk until well combined. Stir in raspberries.

Step 4

Spread the flat side of 1 biscuit with 1 teaspoon filling. Sandwich with 1 biscuit. Repeat with remaining biscuits and filling. Serve dusted with icing sugar.