A cross-linked aminosiloxane polymer includes a first siloxane backbone, a second siloxane backbone, and at least one intramolecular structure cross-linking a silicon atom of the first siloxane backbone and a silicon atom of the second siloxane backbone. The intramolecular structure has the chemical structure: (I) In Formula (I), X is chosen from the following groups; (II); (III); or (IV). In groups (II), (III), and (IV), each R is independently a C1-C10 hydrocarbon group. Each R1 is independently a C1-C10 hydrocarbon group. Each R2 is independently a hydrogen atom, OH, a C1-C12 hydrocarbon group, a phenyl group, R′(OR″)m, or R′OH. Each of R′ and R″ is independently an alkyl group and “m” is 1 to 3. Moreover, “a” is 0 or 1. The cross-linked aminosiloxane polymer can be formed by the method of this disclosure.