A cooking appliance is provided, including a gas burner assembly for a cooktop floor of a cooking appliance. The gas burner assembly includes a burner body having a single combustion chamber and a plurality of flame ports in fluid communication with the single combustion chamber, a first mixing tube in fluid communication with the single combustion chamber and configured to supply a first air-gas mixture to the single combustion chamber, and a second mixing tube in fluid communication with the single combustion chamber and configured to supply a second air-gas mixture to the single combustion chamber.