What is the proper brocha/brachos for a yogurt with small bits of cookies that one mixes into the yogurt?
If the cookies give the yogurt a taste then the bracha would be mezonos, and it is preferable to make shehakol on something else or on some of the yogurt before making mezonos on the cookies. However if the cookies only give a slight taste, but the taste of the yogurt is the main taste then it would be two brachos. See the following link where a similar question was discussed.http://dinonline.org/2017/02/23/bracha-on-croutons-in-a-salad/
See link for sources. As a side point, in the Sharei Habracha pg. 536, he discusses ice cream with cookies inside it, and he says that it is two brachos. In a conversation with the author, he agreed that what he wrote there was only if the taste of the cookies is slight taste, then we clearly make two brachos on it. However if the cookies will give more than just a slight taste, as it is regarding croutons in a salad, then the bracha would only be mezonos with a preference of making a shehakol first.