Combine ground almonds, flour, sugar, salt, baking powder and lemon zest in a mixing bowl. Ensure the ingredients are mixed together then set the bowl aside.
Melt the butter and allow it to cool a little. Put the melted butter, eggs and vanilla extract in a mixing bowl and whisk together.
Add the butter/egg mix to the dry ingredients and mix together until well combined. Cover the mixing bowl with plastic wrap and let it rest for an hour.
Preheat your over to 190c (375f) and spoon the batter into the madeleine tray. Bake in the oven for 10-12 minutes, until they are golden brown. Remove the madeleines from the tray and allow to cool. Sprinkle with icing sugar and serve with lemon curd. http://www.fodmapfoodie.co.uk/recipes/lemon-curd