Preheat oven to 170 degrees celsius (160 degrees cesius fan-forced).
Grease and line a standard sized slice tray (approximately 17X28cm) with baking paper.
Combine the rolled oats, flour, sugar and coconut in a bowl. Set aside.
Place butter, syrup and the water into a microwave-safe bowl and heat for 2 minutes on 70% power (or until the butter has melted). Alternatively you can melt the ingredients in a saucepan on the stove-top (or use the Thermomix method below).
Stir through the bicarbonate of soda.
Pour the butter mixture over the oat mixture and mix through.
Place the mixture into the tray and press down firmly.
Bake for approximately 25 minutes or until lightly golden brown.
Leave in the baking tray to cool for 10 minutes before transferring to a wire rack to cool completely.
When the slice has cooled completely, cut it into slices.