Lightly grease a 20 cm (8 inch) square, nonstick baking tin and line the base with nonstick baking paper. In a saucepan melt the butter, syrup and sugar together. Stir in all the remaining ingredients except the sunflower seeds, then press the mixture into the prepared tin.
Sprinkle over the sunflower seeds, then bake in a preheated oven, 200°C (400°F), Gas Mark 6, for 15 minutes or until golden. Cut into 8 bars, leave to cool, then serve. These bars can be stored in an airtight container for up to one week.