Cookies – way to keep chilled cookie dough from flattening while cutting it

This looks to me like the symptoms of too much flour - probably way too much.

Measuring baking ingredients by volume instead of weight is always a crapshoot, although it shouldn't be that far off - my guess is that either the flour was heavily compacted, or perhaps the baker's mind wandered off and she accidentally added an extra cup.

Overmixing (i.e. by using an electric mixer) is a common problem with cookies but the symptom of that is a hard and gritty cookie that doesn't rise - not one that rises too much and has unbaked flour in the center. As far as I know, that can only happen with a huge amount of flour. Obviously, too much flour would also result in a much denser dough.

What you ended up with seems to be more like a quickbread - almost a scone - and there is indeed not an awful lot of difference between the two aside from the ratios and the creaming of butter.

Excess flour probably wouldn't result in a stickier dough, but stickiness is more due to temperature than anything else. If you're finding the dough too sticky to mold then make sure it's thoroughly chilled - that will make it easier to work with.

Welcome to Seasoned Advice first I will point you to an article in our blog Silpat, Parchment Paper or Plain Baking Sheet. @KatieK contrasts these cooking surfaces.Look at the instructions for time and temp. Are you thoroughly Preheating? You pictures indicate that you are using parchment, but you don't mention time/temp.

My first inclination based on what I see is that you are baking them too long at too low a temp, and not fully preheating. If you raise the temp and shorten the time the cookie will not spread as far. With 'scoop' cookies you expect the dough to spread some, but you are getting too much spread. The higher temperature will cause the cookie to form a solid (ok, solidish, it should be soft but 'strong enough' to hold form) This will also give you better "bottoms" as they will bake faster as well.

Another thing you might be doing is opening the oven door too often, this releases a lot more heat than you think, extending the correct baking time and slowing the process. I know it is sometimes hard to resist peeking, try to not open the door till you are at least 75% through the projected time.