Cookies – Convert chocolate chip cookie recipe to chocolate chocolate chip cookie

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.

The original author is in error adding baking soda (bicarbonate), and indicating it will help rise. For leavening, you require acid for the sodium bicarbonate to react with. The original base recipe has no significant acid ingredients; even the modified version you used has only a trivial amount of acid from the molasses in the brown sugar.

Therefore, the only effect of the baking soda is to increase the pH of the dough, which will encourage browning. However, as the cookies are full of sugar, encouraging browning is not generally a problem.

The creaming method creates bubbles in the solid phase butter, and encourages rising and a more cake-like result, especially when paired with an effective leavening agent.

Resting the dough also hydrates the flour, and allows the butter to re-solidify, both of which inhibit spread and contribute to a higher cookie.

For a chewier result, do not use the creaming method. Melt the butter instead, and then combine your ingredients.

You may also choose to reduce the baking soda to reduce the metallic taste it brings without anything to react with.

If the cookies are now too dense, you might try adding (starting with smaller amounts) 1/2 tsp to 1 tsp or so of baking powder which has its own acid to react with, to help leaven the cookies.

See also:

• What is the purpose of baking soda in chocolate-chip cookies?

• How can I get chewy chocolate chip cookies?

• How do I get my chocolate chip cookies to turn out thick and soft?