• Preheat oven to 160C. Line 2 baking trays with baking paper (for biscuits) or if you'd prefer to make a slice grease and line a 20 cm square baking pan, or small rectangle slice pan with baking paper.
• In a large mixing bowl, combine oats, coconut, flour, and sugar and mix together.
• In a small saucepan, melt butter and golden syrup together. 
• Mix bicarb soda with boiling water and add to the melted butter and syrup mixture. Add this to the dry ingredients and mix well to combine.

To make the biscuit:

• Take a tablespoon of mixture and roll it into a ball and place it on the baking tray. Repeat with the remaining mixture. Bake for 15-20 minutes or until golden, turning trays after about 12 minutes to ensure even cooking. Allow the biscuits to cool slightly on the tray, then transfer them to a wire cooling rack.

To make the slice:

• Press the mixture evenly into the prepared pan and smooth out using the back of a spoon. Bake for 22-25 minutes or until golden brown. Remove from the oven, scatter over the chocolate (small buttons or finely chopped), and return to the oven for 1 minute or 2 to soften the chocolate.
• Remove it from the oven, and use an offset spatula or palette knife to spread the chocolate into an even layer. Set aside to cool and for the chocolate to set (you may need to pop it in the fridge) before cutting it into pieces.