An isothermal cooking plate assembly is formed from a first plate of high thermal conductivity material having a back surface and an oppositely disposed top cooking surface. One or more heater circuit assemblies are disposed on the first plate back surface for forming a composite having a back surface. A controller is in electrical connection with the heater circuit assemblies for controlling temperature of the first plate of high thermal conductivity material. The first plate can be aluminum Type 1100 or aluminum Type 6061. The first plate can be a laminate formed from a clad bottom metal layer and clad top cooking surface metal layer, where the clad layers formed from the same material and having about the same thickness. The clad material can be austenitic stainless steel. A second plate of low thermal conductivity material can be attached to the composite back surface of first plate.