I get a specific question a lot: I do not like coffee that tastes like fruit or lemon, but I also do not want the burnt Starbucks thing, is there something in between? Yes. The category you want is called “natural process Colombian” or “natural process Brazilian.” The words to look for on the bag are natural, honey, or anaerobic.
The reason those beans taste like chocolate cake and not lemon is the processing. When coffee cherries are dried with the fruit still on the bean (natural process), the bean absorbs sugars and takes on notes that people describe with words like cocoa, caramel, brown sugar, and sometimes red wine. When cherries are washed clean before drying, you get the bright acidic notes people either love or find alarming.
Try a medium-roast natural process Colombian, brewed as a pour-over with a 1:16 ratio, and if it still tastes bitter to you it is not the bean, it is the water or the grind. Try again. Coffee that is genuinely bitter is coffee that was extracted too hard. Coffee that is sour is coffee that was under-extracted. Neither is inevitable. And the chocolate-cake thing is not a metaphor — done right, that is what the cup actually tastes like.