A method for preparing an aluminosilicate molecular sieve having the SSY framework structure is described. The method includes (1) a step of preparing a reaction mixture containing an aluminosilicate zeolite having an FAU framework type; N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium cations and/or N-ethyl-N-(2,4,4-trimethylcyclopentyl)pyrrolidinium cations; an alkali metal; hydroxide ions; seed crystals; and water; and (2) a step of subjecting the reaction mixture to crystallization conditions sufficient to form crystals of the aluminosilicate molecular sieve. The resulting molecular sieves are useful as catalysts, particularly when used in combination with exchanged transition metal(s).