Some of the people who follow the diets advocated by any of the well known people in the paleo and primal world will post 'baked' goods at their sites. The best of these recipes will use things like egg whites to incorporate air, and nuts and coconuts as flours or ground up. You will also come across 'foods' made with lots of seed products, cream cheeses, and chemical alternatives and shortcuts. You'll also find that people who post these recipes may well use lots of honey, maple syrup and (processed) stevia.
The guide should be that if you have to process or chemically make it, then don't use it. Baking powder is not naturally occurring and neither is stevia powder. If you want to take an hour then you could beat egg whites with a stick - but in the wild you would rarely have had the huge abundance of eggs that we have now. The idea of making paleo pancakes (as in Rob Wolf's book) is something that we might do now as a compromise of modern availability, lifestyle, knowledge and technology, but would have been far less likely as part of an evolutionary diet.
Sweet 'paleo muffins' made with a rising agent (chemically processed), and nut flour (imagine grinding this up by hand) with loads of honey (this is possible but would have been a lengthy and dangerous undertaking) or stevia (the leaves are sweet to chew but you would have to use a lot of leaves and grind them up) seem less paleo the more you look at how you have to make them.
If you really, really want to make a neolithic style dish (and let's face it, we have the knowledge and the technology) then it's really best to make everything from scratch so you can really see how much stuff you are using and how much time it actually takes. It's also a good idea to make the dish without any sweetening at all (or at the most allow only about a half teaspoon of honey a serve) - that's a pretty good guide of where your taste buds are at and how far you are from paleo.