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Just to add to @Daniel's answer, if your Location dropdown is greyed out you may have selected the wrong file. Make sure to select the framework that's in your app project (not framework project).
This it the only way i have discovered to restore the embedded binaries, please leave comments if you find some steps are not required.
Prerequisites: Read Daniel Tull's answer.
When you add the framework to the Embedded Binaries, there will be a reference added to your project for it. If you select that reference after your steps above, you will probably find that it has an Absolute Path reference to the framework rather than a relative one, which we'd like. Change the location to Relative to Build Products and the reference should always be discoverable if do a "hard" clean or use another computer etc.
I have made a video which describes how best to add a built framework from one project to an app target in another sibling project.