My plan has been to use this blog/site for sharing favourite and reliable recipes. This is the first time I am sharing a first time recipe, so the Notes and Tips will be a bit more detailed.  I have a fairly large "repertoire" of cookie recipes and make dozens, especially at Xmas. The road to cookie perfection can, for me, be a bumpy road. I often think my oven is wonky, though tests of oven temp would belie that. Recently I bumped into info that suggested the "problem" might be my (old) cookie sheets. (See this discussion.) So I ordered new cookie sheets (rated best by America's Test Kitchen - ATK). They arrived and I had to test them! A "scientific" test would have had me making a recipe I have done before, but I complicated the experiment by failing to resist the temptation to try a new recipe. Coffee and Toffee - that was hard to resist. So here's the recipe from ATK's 2013 Christmas Cookies edition - and/but do note all the Notes at the bottom which I think will result in an even better cookie next time.

This recipe is mixed by hand - no need for a mixer. Requires two bowls and two cookie sheets. Makes 24 large cookies.

Adjust oven rack to upper middle and lower middle position and heat oven to 350° F. Line 2 baking sheets with parchment paper.  Always ideal to prep all ingredients. Melt the butter just before starting - it should still be slightly warm at the moment it is added.

2 cups (10 ounces) all-purpose flour
3/4 tsp baking soda
1/2 tsp salt

(If bowls are not the same size, use the smaller one to mix dry ingredients.) Whisk flour, baking soda and salt together in the bowl.

2 TB instant espresso powder 
1 TB hot water 

10 TB unsalted butter, melted 
1/4 cups (8 3/4 ounces) sugar 

2 large eggs 
1 tsp vanilla extract 

3/4 cup (4 1/2 ounces) toffee chips

Whisk espresso powder and hot water together in large bowl until espresso powder dissolves.

Then whisk in butter and sugar until incorporated.

Since I am mixing by hand, I prefer to slightly beat the eggs before adding them to the mix. Whisk in eggs and vanilla until smooth.

Using rubber spatula, gently stir in flour mixture until soft dough forms. Fold in toffee chips. 

Drop six 2 TB mounds of dough onto each prepared sheet, spacing them about 2 inches apart. Bake until edges are set but centres are still soft and puffy about 16 minutes, switching and rotating sheet's halfway through baking. Let cookies cool slightly on sheets and serve warm, or transfer to wire rack and let cool completely before serving. Repeat with remaining dough.

Notes and Tips...

  • Flour - as I have mentioned before, when ingredient weights are offered in baking recipes, I prefer to weigh the ingredient using my digital scale.
  • Salt - I have some salt "research" I have not yet had a chance to post - but there is some consensus that it is not ideal to use kosher / coarse salt in cookies. (Will post this info soon.)
  • Instant Espresso Powder - I use Medaglia D'Oro - and must say I have had a terrible time of late sourcing this locally. I was all set to order this from Amazon until I discovered the wonderful Vincenzo's in Waterloo. ATK notes stress that regular instant coffee should not be used as a substitute since it lacks the "concentrated flavor that add dimension and depth". I seem to have a lot of cookie recipes that call for instant espresso powder so I will soon have to re-stock.
  • Butter - while most ATK recipes work well, there was one that gave me grief. My theory was that the cookie dough needed more "fat" - and I did have a theory on that... I communicated with ATK and they confirmed that they use "European Style" butter, meaning 84% fat. (See my notes on butter.) Up until now, I have had success with their recipes using regular (non 84%) butter. This was the first time I decided to do "everything by the book" and use 84% - unsalted, of course - and not every store that carries Stirling 84%, carries the unsalted version!
  • Toffee Chips - I assumed they meant "toffee bits" (as in something like Hershey Skor Toffee bits.) 
  • Mixing - ensure that the flour is fully incorporated. At first it seems like a "mixture" but then begins to behave more like a "dough"
  • Bake prep - I always use a scoop for portioning the dough - I used one that technically did not hold 2 TB of liquid, and yet oddly it did work in measuring 24 cookies.
  • Baking - I have mentioned before that I prefer to bake one sheet of cookies at a time, but since I finally had two identical sheets, I decided to do the recipe as exactly as possible and did two sheets at a time. (I didn't use convection.) I had begun the habit of checking (removing) baking before the specified time. This time I went for the full 16 minutes as specified - although... that was past their descriptor - "until edges are set and centers are soft and puffy". I think in future I'll go for 14 minutes- that will make them a bit gooey-er in the centre. 
  • Eat warm - ATK admits these taste best from the oven - agreed. But.. I discovered that you can put a few cookies in the microwave for no more than 15 seconds and - zowie! - they taste like fresh from the oven.
  • Next time I might try these modifications:
    • shorten baking time
    • maybe add a bit more of the espresso powder to ramp up the coffee flavour (that does not mean I will increase the liquid...)
    • I might check the bulk barn to see if I can get toffee bits that are slightly larger; or... I might smash up a Skor bar - and introduce some chocolate to the experience.
    • The second it comes out of the oven, when the centre is still a bit moist, I plan to do a light sprinkle of sea salt - yummy.
    • I prefer smaller cookies, so may experiment with that and a modified bake time.
    • Somewhere, I saw a similar recipe that suggested melting the butter to the "brown butter" stage - that might be interesting