• Preheat the oven to 180˚C/ 355 ˚F
• Lightly grease a baking sheet.
• Combine the flour, cocoa and sugar in a roomy mixing bowl.
• Add the margarine and beat together until the mixture forms a smooth paste, it is easier to start off mixing with a spoon and then use your hands.
• It will look very crumbly at first, but it will come together.
• If it doesn't seem to be getting less crumbly, add ½ teaspoon of milk.
• Bring the dough together to form a ball.
• Place the dough in between 2 sheets of baking paper, and roll out out to a thickness of 4-5mm (.15" -.19")
• Cut into an even number of shapes with a cutter or use a knife to cut rectangles 7cmx 3.5 cm (2.8" x 1.4")
• Transfer to the prepared baking sheet.
• If you want to add some decoration to the biscuits, carefully press the blunt end of a skewer along the longer edges of the biscuits, taking care not to press right through the dough.
• Place in the oven and bake for 8-9 minutes.
• Leave for a minute on the tin, and then move to a wire rack to finish cooling
• When the biscuits are cold, make the chocolate buttercream.

To Make the Buttercream

• Melt the chocolate in the microwave or over a pan of boiling water.
• Beat the butter/margarine until soft, then sift the sugar into it, and pour in melted chocolate. Mix to combine.
• Spread a teaspoonful of the buttercream onto half the biscuits (taking care as they can be crumbly), then top with the other biscuits, moving around slightly to squidge the filling to the edges – not too much or the filling will escape!
• Store in an airtight container.