Despite tremendous interest in inverted architecture perovskite solar cells the PCE of such devices lags behind, with maximum values rarely approaching 23%. The generally lower performance of inverted architecture perovskite solar cells is mainly associated with reduced current extraction and nonradiative recombination losses which limit the device photovoltage and fill factor. The development of strategies to overcome such limitations has been subject to intense research, including interface and bulk passivation of traps, such as crystallographic defects, point defects or higher dimensional defects (at grain boundaries). Predominantly, these approaches led to an improvement in device performance due to increased open-circuit voltage (VOC), with fill factors (FF) remaining in the range of 75-80%. This highlights the need to develop new methods that would simultaneously improve the VOC and the FF of inverted architecture devices. Herein, we demonstrate an innovative strategy for the dual modification of both the HTL/perovskite and perovskite/ETL interfaces by introducing a series of large organic cations: 2-phenylethylammonium iodide (PEAI), 4-chloro-phenylethylammonium iodide (Cl-PEAI) and 4-fluoro phenylethylammonium iodide (F-PEAI) in both these interfaces. Despite this class of cations being commonly utilized for the formation of low dimensional perovskites, in our work, we adopt a different strategy and use a very low concentration to modify both interfaces of inverted perovskite solar cells. We find that this approach does not change the bulk perovskite crystal structure or its of dimensionality, but rather improves the interfaces by facilitating high-quality film formation on top of the HTL and inducing efficient defect passivation at the perovskite/ETL interface. We show that the modification of the buried bottom interface leads a more homogenous film formation and the elimination of nano-voids at the perovskite/HTL interface. These improvements result in a significant increase in the fill factor accompanied by an increase in the short-circuit current (JSC). The modification of the top perovskite surface, on the other hand, leads to its efficient passivation, resulting in a substantial increase in the VOC. Importantly, the implementation of both modifications at the same time results in a simultaneous increase in all of the photovoltaic parameters leading to a superior device performance. As a result, we achieve a high PCE of 23.7%, with a net improvement of device VOC up to 1.184 V and very high FF of 85%.