The paper introduces a novel approach to realizing optical metamaterials, focusing on the use of twisted optical metamaterials for planarized, ultrathin, broadband circular polarizers. Traditional optical metamaterials are typically based on planarized, complex-shaped, resonant nano-inclusions, but three-dimensional geometries can provide broader functionalities, such as broadband chirality for manipulating circular polarization. However, their fabrication becomes challenging as dimensions decrease. The authors propose a new paradigm where three-dimensional effects are achieved not through complicated inclusions but by tailoring the relative orientation within the lattice. They apply this concept to create stacked nanorod arrays with a tailored rotational twist, which effectively operate as three-dimensional helical structures with broadband bianisotropic optical response. This approach relaxes the alignment requirements common in three-dimensional metamaterial designs, making it easier to fabricate. The paper demonstrates that by cascading two identical plasmonic metasurfaces with a subwavelength separation distance and a specific rotation angle, strong circular polarization selectivity can be achieved. The transmission coefficients for left-handed (LCP) and right-handed (RCP) waves are analyzed, showing that a right-handed rotation of the second array relative to the first produces preferential transmission of RCP waves within a moderate wavelength range. The functionality and robustness of the twisted metamaterials are further explored, showing that they can maintain performance even with misalignments between neighboring layers. Experimental realization and characterization of devices ranging from one-layer to four-layer stacks confirm the broadband circular polarization capabilities of the proposed design. The authors suggest that this concept can be scaled up to longer wavelengths, potentially enabling applications in the mid-infrared and terahertz spectral ranges. The proposed twisted metamaterials offer a promising approach for integrating broadband circular polarizers into nanophotonic systems due to their ultralow and planar profile.The paper introduces a novel approach to realizing optical metamaterials, focusing on the use of twisted optical metamaterials for planarized, ultrathin, broadband circular polarizers. Traditional optical metamaterials are typically based on planarized, complex-shaped, resonant nano-inclusions, but three-dimensional geometries can provide broader functionalities, such as broadband chirality for manipulating circular polarization. However, their fabrication becomes challenging as dimensions decrease. The authors propose a new paradigm where three-dimensional effects are achieved not through complicated inclusions but by tailoring the relative orientation within the lattice. They apply this concept to create stacked nanorod arrays with a tailored rotational twist, which effectively operate as three-dimensional helical structures with broadband bianisotropic optical response. This approach relaxes the alignment requirements common in three-dimensional metamaterial designs, making it easier to fabricate. The paper demonstrates that by cascading two identical plasmonic metasurfaces with a subwavelength separation distance and a specific rotation angle, strong circular polarization selectivity can be achieved. The transmission coefficients for left-handed (LCP) and right-handed (RCP) waves are analyzed, showing that a right-handed rotation of the second array relative to the first produces preferential transmission of RCP waves within a moderate wavelength range. The functionality and robustness of the twisted metamaterials are further explored, showing that they can maintain performance even with misalignments between neighboring layers. Experimental realization and characterization of devices ranging from one-layer to four-layer stacks confirm the broadband circular polarization capabilities of the proposed design. The authors suggest that this concept can be scaled up to longer wavelengths, potentially enabling applications in the mid-infrared and terahertz spectral ranges. The proposed twisted metamaterials offer a promising approach for integrating broadband circular polarizers into nanophotonic systems due to their ultralow and planar profile.