Hi. First of all, you have to determine if your brownie and cupcake recipes require natural cocoa (like Hershey's and Ghirardelli) or Dutch-processed a.k.a. alkalized cocoa (like Dutche and Bensdorp) because they are not always interchangeable. Read the label or ask your seller to find out which is which. My cocoa of choice has always been the latter.
Natural cocoa is lighter in color and somewhat acidic with a strong chocolate flavor. In baking, use natural cocoa in recipes which call for baking soda. Combining natural cocoa which is an acid with an alkali such as baking soda creates a leavening action which allows the batter to rise during baking.
Dutch-processed cocoa has been processed with alkali to neutralize its natural acidity thus making it darker (sometimes with a reddish cast), milder in taste and less acidic than the non-alkalized kind - even though its color suggests that it is the stronger flavored of the two. Use Dutch-processed cocoa in recipes which call for baking powder as the primary leavener. If alkalized cocoa is combined with baking soda in a cake recipe, it will create an overabundance of alkali in the batter. As a result the batter will not rise properly, might not set within the prescribed time and the finished product will have a soapy taste.
I think this is what happened when you used Dutche which you said gave you inedible results. I have used this brand in recipes specifying Dutch-processed cocoa and was quite satisfied with it. I have also used it in recipes asking for natural cocoa but I had to add an acidic ingredient like buttermilk powder in a commensurate amount to neutralize the increased alkalinity. The principle applies to all brands of Dutch-processed cocoa. With that in mind, you might want to give Dutche a second chance.
In recipes where no leavening is required - neither baking powder nor baking soda is present - you can use either type of cocoa.
There is no disputing the fact that premium brands like Bensdorp, Valrhona, Callebaut, Lindt and Ghirardelli have far better quality which understandably comes with much higher and even staggering price tags. But I firmly believe that superior quality does not always have to be pricey. Try checking out more pocket-friendly yet worth recommending brands like De Zann and KLK which are even less expensive than Hershey's. Feel free to ask your seller - most baking and confectionery supplies stores like Chocolate Lovers, Sweetcraft, Bakers Depot, Bakemaster and Carla's (the last two in Sucat, Parańaque City) can recommend the cocoa brand which best fits your budget. If you rely mainly on the supermarket as your source, then go for the usually reliable Hershey's, the much improved Goya and even Ferna which I have also tried with fairly good results. Oh, as already mentioned, don't count out Dutche just yet.