Whoopie pies

Lemon butter

• 40 g lemon juice (approx. 1 lemon)
• 90 g caster sugar
• 80 g unsalted butter, cut into pieces
• 2 eggs

Whoopie pies

• 250 g plain flour
• 2 tsp baking powder
• 1 pinch salt
• 150 g caster sugar
• 1 lemon, zest only, no white pith
• 120 g unsalted butter, cut into pieces and softened
• 1 egg
• 100 g full cream milk
• 1 tsp natural vanilla extract

Assembly

• icing sugar, for dusting