Preheat the oven to 350 and line a half sheet pan with parchemnt paper
Add the butter, sugar and syrup to mixer and beat together until creamy
Add the oats, baking soda, salt, flour and rye flour to the bowl and mix again until combined.
Portion the cookies into 45 gm balls.
Press each cookie down by half and place onto the lined trays
Bake in the oven for 15 minutes, and then leave to cool fully on the trays.