Run perfmon.exe. If you define a data collector set, you can set up counters for things like "% Processor time", and you can set it up to look at the Total or select it by core.
Once you have this set up, you can start and stop it, and review the results in the "Reports" section. There are a variety of ways to export the raw data -- just google for "export perfmon data to CSV" or "export perfmon data to Excel"
Keep in mind when you are profiling, that it does put a load on the computer -- so be careful with how many counters you have running, and how frequently you update them.