They turned out really well, very chocolaty and a light texture, definitely recommend these...
2 teaspoons lime zest, finely chopped
¾ teaspoon granulated sugar
¼ cup plus 2 tablespoons all purpose flour
½ stick (2 oz) unsalted butter, cut into pieces
2 ½ oz high quality bittersweet chocolate, coarsely chopped
1/3 cup soft light brown sugar
¼ teaspoon vanilla extract
1 large egg
1. Heat the oven to 350ºF. Grease 2 x 12 hole mini muffin pans or use liners.
2. Mix together the orange zest and granulated sugar, set aside. Whisk together the flour and salt, set aside.
3. In a heavy saucepan melt the butter, chocolate and brown sugar – stirring all the time until smooth. Leave for a minute off the heat then stir in the vanilla, egg and zest mixture. Lastly add the flour and salt and mix lightly until it is smooth and shiny.
4. Divide the batter evenly among the muffin cups and bake for 9-10 minutes.