Tips and Tricks
Butter
1) I like using Lactancia cultured butter as it gives better flavor, but butter must sit at room temp for a few hours to soften -cultured butter can stay at room temp overnight - or its really hard to whip
2) whipped shortbread is essentially buttercream icing with the cornstarch to stabilize the flour so the cookie doesnt crumble like crazy when you try to pick it up after its baked... so the tinny bit of salt in salted butter is negligible
3) Do not use margarine as it changes up the taste profile... and have traditional bakers poke at you with pitchforks. If you are short on butter and must use margarine, don't sub out more than 50% of the butter, and never use low cal, light or whipped margarine as it has too much water content and your cookies will resemble asphalt
Sugar
1) Do use icing sugar and not regular sugar. The powdered form of icing sugar gives the whipped shortbread the airy, melt in your mouth like a cloud mouthfeel... As does all the air you incorporate with the long mixing time.
Flour
I buy my flour pre-sifted as I'm lazy/ efficient. Sifting it gets rid of large lumps, and makes it easier to add air to the batter as the mixer doesnt have to break apart the flour lumps
Toblerone chopped size
1) You can use other chocolate if you have allergies, but Toblerone does really make these cookies decadent and over the top
2) If you are Martha-Stewart OCD and want to pipe out the cookies with a nice icing tip to make the cookies look nice, make sure you finely chop the chocolate into pieces no bigger than what can fit out of your icing tip, or just pipe out the cookie dough and embed a large chunk in the middle of the cookie
3) Personally, I like a rough chop with a knife as you get fine bits that blend into the cookie, and larger chunks that form pockets of melted yumminess... I chop the Toblerone pieces no bigger than 1cmx1cm chunks
To cookie scoop or to drop cookie...
1) if you want a fancy pants cookie, you can scoop batter into an icing bag with a large bore icing tip and pipe out the batter into circles with spirals
2) If you want the traditional "dome" look, scoop out the cookie dough with a cookie scoop -if you are low on time or like a homemade look, scoop with a spoon and drop the cookie onto the cookie sheet -if your oven is hot and your cookie dough starts to get runny, pop the dough into the fridge for a few minutes before scooping/piping
How long to bake cookies and oven temp
1) shortbread traditionally isn't supposed to have golden bottoms (sacrilege!), but its not the end of the world if you do.. Still tasty! The lower the heat, the longer it takes to bake, but less likely you'll "ruin" the cookies by overbaking it. The lowest I've personally tried baking these cookies are 275F for 30-35 min. But when you need to make multiple batches during Christmas baking time, as long as you are ok with maybe overcooking your first batch (all ovens vary a bit with temp), you can bake them at 300F for 18-20min. I've tried temps as high as 400F, for 8-10 min which is super fast for baking time , but I find the edges (if not whole cookie) is a crispy golden brown.
Do I have to use parchment paper if I'm using a good non stick cookie sheet?
1) If you want to transfer the cookies with out them breaking/ crumbling as they are super delicate and save your sanity, a unch of swearing (and your waistline), yes.
2) Tin foil works, but transfers too much heat so you may get odd overcooked spots on bottom of cookies. Wax paper works too, but I personally hate how the wax smokes in the oven and I'm always afraid of it going up in flames if I reuse the same sheet for subsequent batches.
1 cup salted or unsalted butter at room temp
0.5 cup icing sugar
0.25 cup cornstarch
1.5 cups all purpose flour, sifted
1.25 cup Toblerone chopped (exclude if you want traditional whipped shortbread)
How to
1) Move oven rack to 2/3 up in the oven (level you usually bake cookies and muffins on). Preheat oven to 300F.
2) In a mixer with a large deep mixing bowl and paddle attachment (ideally not a hand held one as you'll be holding it for a while), whip together the icing sugar and butter on low (keeps the sugar clouds exploding all over kitchen down to a minimum) and once incorprated, crank the mixer on high for 10min, scraping the sides of the bowl every now and then with a silicone splatula -the batter will be very light in color and fluffy like icing.
3) turn the mixer on low, and add in the cornstarch and flour to the sugar-butter mixture. Once mixed in, turn the mixer on high, scraping down the sides of the bowl with a silicone spatula occasionally and mix for another 5 min. If you walk away and mix for longer, it's ok. The batter should resemble super fluffy icing.
4)Turn off mixer, and fold in chopped Toblerone with a spatula. Using a small cookie scoop or a teaspoon with a generous gob of dough, place cookie dough on parchment paper lined cookie sheets 1inch apart and bake for 18-20min. They are done when you can lightly tap the top of the cookie and the dough is set and not liquidy.
5) Let the cookies rest for 10min on the cookie sheet and then transfer cookies to a cooking rack. If the bottoms are starting to overcook, or you are afraid to break the cookies, lift parchement paper with cookies and place the whole thing onto a cooling rack-that way you dont have to transfer them one by one risking breakage. Once cookies are cool, they wiill set and be more firm and you can transfe to gift boxes or air tight containers with parchment paper inbetween layers to help prevent breakage. I eat all the blemished/broken cookies... Feel free to do the same. Enjoy!!