Gluten-free lemon melting moments

Preheat oven to 150°C fan-forced (170°C conventional). Line 2 oven trays with baking paper.

Combine butter, sugar and vanilla in a medium bowl and beat with the paddle attachment of an electric mixer for 2-3 minutes, until combined. Add egg and beat until just combined. Stir in sifted flours and xanthan gum, in 2 batches. Cover and chill for 10 minutes, if needed, to firm up dough slightly.

Using wet hands, roll tablespoonfuls of mixture into 16 balls. Arrange balls on prepared trays spaced 5cm apart and flatten slightly with a fork dusted in a little extra gluten-free plain flour.

Bake cookies for 20 minutes, or until bases are light golden and tops are still pale. Cool fully on trays.

To make lemon buttercream, beat butter and sifted icing sugar mixture in a small bowl with an electric mixer until pale and fluffy. Beat in lemon zest.

Transfer buttercream to a small snaplock bag and snip a 1cm corner from the edge. Pipe buttercream onto half the biscuits, then sandwich with another biscuit. Dust with icing sugar to serve.