•Preparation of bilayer of CoFe2O4/ZnFe2O4 on quartz substrate which results in large magnetization after annealing.•The obtained room temperature magnetization is higher than any binary ferrite and is close to metallic Nickel.•The highest magnetic moment value cannot be explained by Néel model. In this paper, we report our observation of an extraordinarily large value of magnetization in an annealed CoFe2O4/ZnFe2O4 bilayer. Sets of bilayers of CoFe2O4/ZnFe2O4 were deposited at ambient temperature, using pulsed laser deposition setup equipped with Nd: YAG laser, and subsequently annealed in air at different temperatures for 2 h. The highest attained value of magnetization was ≈7200 G at 300 K and ≈15000 G at 10 K for a bilayer with a 60 nm thickness tCo of CoFe2O4 and 40 nm thickness tZn of ZnFe2O4, annealed at 650 °C. This measured magnetization value is the highest for any oxide spinel reported thus far in the literature. The observed value is close to that of metallic Ni and cannot be explained by current theories of magnetism in oxides.