In the presence of decaying potentials at late times, large rare superstructures in the universe imprint secondary temperature anisotropies on the CMB via the integrated Sachs-Wolfe effect. This effect might be measured by stacking analyses, but these have been controversial, due to a long-standing discrepancy between one such measurement and the LCDM theoretical expectations. I will present a new method for detection of the stacked ISW signal based on the construction of an optimal matched-filter for the CMB. Applying this method to our new catalogue of superstructures from SDSS DR12 data allows a very precise measurement of the ISW amplitude, at high statistical significance. I will show how the new measurement resolves the tension with LCDM theory, compare the result to other recent measurements including by the Dark Energy Survey, and discuss the implications for the CMB Cold Spot anomaly.