175g(3/4 cup, 1 1/2 sticks)) butter, plus extra for greasing
125g(5/8 cup) light muscovado (brown) sugar
200g(1 1/4 cup) dark chocolate, melted
*It is best to measure this in grams as Donal has written the recipe. Conversions are always a little off, though a good approximation.
Preheat the oven to 180°C (160°C fan). Grease a shallow 18cm square baking tin and line with parchment paper.
Put the rolled oats in a large bowl with the desiccated coconut and sunflower seeds, around 1-2 tbsps.
Melt the butter, sugar and maple syrup in a pan over a low heat until the sugar has dissolved, then pour it into the rolled oat mixture. Mix well, then pour the mixture into the prepared tin and press down well.
Bake in the oven for about 20 minutes, or until golden brown. Allow to cool completely in the tin on a wire rack. With a sharp knife loosen round the edges.
When firm and cool, pour over the dark chocolate and spread evenly over the surface. Allow to set in a cool place before removing from the tin and slicing into rectangles.