Flat, flatter, flattest

I’m not sure what I’m doing wrong but my chocolate chip cookies are flat and spread out too much.

I follow the Nestles Tollhouse cookie recipe using room temperature butter and measure out the ingredients exactly as written.

The butter was room temperature but not real soft.  I used a hand mixer for this batch and some leftover mini chocolate chips and chocolate chunks (bought by mistake).

The cookies are very tasty but we now have to eat the entire batch as they aren’t “pretty” enough to share with the neighbors.  I know, tough job but somebody’s got to do it.

My oven might be too hot.  I may have over mixed the ingredients.  My dough was room temperature and perhaps not cool enough before baking.  Any other ideas as to what went wrong?