Combine one bottle of Amstel Radler beer, sugar, salt, cinnamon, bay leaf, peppercorns and cloves in a sauce pan.
Place over medium heat and stir until the sugar and salt are dissolved.
Remove from heat and let to cool to room temperature.
When fully cool, add the second bottle of Amstel Radlerbeer and mix to combine.
Lay the chicken breasts on the bone, skin-side down, in a shallow glass or ceramic dish.
Pour the cooled beer mixture over the chicken. Cover well and refrigerate the chicken for a minimum of 4 hours but preferably overnight in the fridge.
When ready to cook, transfer the chicken from the marinade to a clean plate and allow it stand for 20 minutes to allow it come to room temperature.
Melt the butter in the microwave in a small bowl and stir in the chilli powder and cayenne pepper (if using).
Pour the chilli butter over the skin on each chicken breast, brushing it around to ensure good coverage.
When ready to cook, place a griddle pan on the stove and heat to a high temperature.
When the pan is just beginning to smoke, lay the chicken breast skin-side down on the griddle pan.
Cover and allow it to cook undisturbed for 15 minutes.
Turn the chicken breast, cover and cook for another 10 minutes.
Check the chicken is fully cooked (the juices should run clear and the inside will no longer be pink if fully cooked) .
If necessary, continue to cook it in 5 minute increments until it has finished cooking fully.
(You can sear the chicken on the griddle pan and transfer to a baking dish cooking for 40 minutes or until fully cooked if you prefer).
Place the cooked chicken breasts onto a clean plate and cover with aluminium foil to allow them rest for 10 minutes before carving.
Slice the breasts into thin pieces and serve.