Line a baking sheet with a silicone baking mat or parchment paper and set aside. DO NOT use wax paper, the high heat from the toffee can melt it!
Place a small heavy-bottom saucepan on medium heat. Add in the butter, brown sugar, and salt. Stir as the butter melts.
113 grams unsalted butter, 220 grams dark brown sugar, 1 teaspoon fine sea salt
Once the butter is melted, whisk vigorously to combine. (vigorously is important at first! stir to slow and it will separate) Continue whisking constantly as the mixture cooks, to prevent burning. It should go from a dark brown color to a lighter caramel color.
If the mixture does separates while it's cooking, remove saucepan from the heat and stir vigorously again until it comes back together. Return pan to the heat and continue cooking.
Cook until it begins to resemble peanut butter 7-9 minutes, an instant read thermometer should read to 295°F (146°C) for "hard crack" candy.
Immediately remove from heat and pour the toffee onto the prepared baking pan. It should be easy to pour but have a thick texture. Careful when pouring as the mixture will be very hot. Spread the toffee into an even layer with a silicone spatula. The toffee will start to firm as soon as it hits the tray.
Let cook for about 20 minutes, or until it reaches room temperature. It should be firm enough to pick up into one big sheet of toffee.
Chop the toffee into small chunks with a large knife, just like you would chocolate chips and set aside.
Measure out 100 grams (1 cup) of the chopped toffee bits for the cookie dough. Store the leftovers in a plastic bag in the fridge or freezer for another recipe.
Toffee Cookie
In a medium bowl, whisk together the flour, baking soda, baking powder, cornstarch, and salt. Set aside.
333 grams all purpose flour, 2 teaspoons cornstarch, ¾ teaspoon fine sea salt, ½ teaspoon baking soda, ½ teaspoon baking powder
Place butter, brown sugar, and granulated sugar in the bowl of a stand mixer or large bowl with electric hand mixer. Cream together on medium-high speed for about 1-2 minutes until the butter is completely incorporated into a sugar paste.
227 grams unsalted butter European-style, 265 grams dark brown sugar, 50 grams granulated sugar
On medium speed, beat in the egg and egg yolk until well combined. Followed by the vanilla.
1 tablespoon vanilla bean paste or pure vanilla extract, 50 grams egg, 20 grams egg yolk
Mix in the flour mixture, half at a time until just combined.
Add the toffee bits and mix on low for a couple spins, just to mix them in. Or use a sturdy silicone spatula to fold them in by hand and avoid overworking the cookies dough.
100 grams homemade toffee bits
Pre-scoop the cookie dough using a large cookie scoop. Place the portions on a parchment paper lined tray or air tight container. Cover and refrigerate for a minimum of 3 hours or overnight.
Preheat oven to 350℉ (180℃). Line a cookie sheet with parchment paper.
Place cookie dough balls about 3-inches apart of the baking sheet. I bake four large cookies at a time.
Place tray on middle oven rack and bake for 14-15 minutes. The centers should look puffy and the edges a golden brown.
Transfer cookie sheet to a wire cooling rack and sprinkle with flaky sea salt. If the cookies are slightly misshapen, use a large round cookie cutter or glass to "scoot" around the cookie in a circular motion to re-shape them into a circle. (*see post for details)
flaky sea salt
Leave cookies on the hot pan for about 10 minutes to finish setting up. Then transfer directly onto a wire rack to cool completely.
Video
Notes
Ingredients Used:
Flour: Gold Medal All Purpose 10.5-11% protein
Butter: President Unsalted Butter, 82% butterfat
Toffee: This recipe was tested with homemade toffee, which melts into pools of toffee in the cookies.
Substitutions:
Gold Medal Flour or a soft wheat flour with 11% protein will yield a tender cookie with a slight spread. King Arthur Flour, a strong wheat flour with 11.7% protein will yield a slightly thicker cookie with less spread.
The ratio of flour to butter is adjusted for the rich European-style butter used. Swapping for American style butter with only 80% butterfat will result in a less tender cookie.
Oven: This recipe was written for a conventional oven (top and bottom heat). For convection fan ovens, reduce the temperature by 25 degrees and begin checking for doneness 75% of the way through baking.
Weigh your flour: The measurement I use: 1 cup of flour equals 125 grams. This amount can change based on a different baker’s recipe or using a conversion tool. The weight listed in the recipe is how it was tested and should be used for accuracy.Different brands of flour are made with soft or hard wheat and have varying levels of protein, ranging from low to high. This can change the final result of a baked good, giving different outcomes on the same recipe. I list the level of protein in the ingredients, the brand of flour tested with and a link to My Baking Ingredientsfor additional details. When choosing a flour, look at the protein level on the back of the bag and consult the recommended amount for the recipe.