I’m going to agree with @simba9 in saying that you definitely don’t need to limit yourself to colleges with cognitive science and computer science majors.
Most colleges have computer science majors, so that’s not a problem.
Cognitive science is largely an interdisciplinary major that includes coursework from several departments/fields. Psychology, computer science, linguistics, and neuroscience are usually most heavily represented, but sometimes students also take classes in anthropology, philosophy, and other fields. Even if you look at Vassar’s (deservedly vaunted) cognitive science program, most of the courses are ones that are readily found in other majors, and the concentration is all made of courses you actually DO take in other departments.
So you don’t necessarily need a university with a cognitive science program; you could simply supplement your CS major with a lot of the coursework that you would take in a cognitive science major offered through other departments. Most of it will be offered at any college with psychology coursework; having a linguistics and/or neuroscience program would be a sweet bonus.
But as additional suggestions:
Stanford has a major in Symbolic Systems, which is essentially a different name for the same thing: https://symsys.stanford.edu/
Carnegie Mellon is a good choice, too: They have strong computer science and strong psychology with a BS in cognitive science housed in the psychology department. They also have linguistics and neuroscience AND majors like Decision Sciences and Human-Computer Interaction which will probably also be interesting to you.
RPI has both as well.
Depending on your stats, Lehigh University, Occidental College, Case Western, University of Rochester and University of Richmond may be high matches or straight up matches for you, and they all have both majors.
Villanova, Marquette, Syracuse, and Beloit may be good low matches or safeties. Hampshire College is probably a safety, and they have a School of Cognitive Science.
And if Canadian schools are a consideration, the University of Waterloo has an excellent CS program and also has cognitive science.