A cable includes an inner layer surrounding a conductor and an outer layer surrounding the inner layer, and the outer layer is formed from an extruded outer layer composition including an at least partially cross-linked resin including a base polyolefin and a weak acid source, an inorganic flame retardant, and one more of an organic char former and a spumific agent. The cable passes the Underwriters Laboratory ("UL") 1581 VW-1 Flame Spread Test and one or more of the UL 44 Long-Term Insulation Resistance Test at 90° C and the ceramifying requirements of International Electrotechnical Commission ("IEC") 60331-21. Methods of manufacturing such cables are also disclosed.