Preheat your oven to 400°F (200°C). Line a 9x9-inch baking pan with parchment paper, ensuring it hangs over the edges for easy removal. Arrange saltine crackers in a single layer on the bottom of the pan.

In a medium saucepan, combine 6 tablespoons of salted butter and 6 tablespoons of brown sugar. Heat on medium, stirring constantly until the mixture comes to a boil. Allow it to boil without stirring for about 2½ minutes, then pour evenly over the saltine crackers.

Bake for 6 minutes until the toffee is bubbly and golden.

Remove the pan from the oven, and immediately sprinkle ¾ cup of chocolate chips over the hot toffee. Let it sit for a few minutes to melt, then spread it over the toffee using a spatula. Allow it to cool completely at room temperature before placing it in the freezer for at least 30 minutes.

In another saucepan, brown 1 cup of salted butter over medium heat until golden brown. Let it cool slightly. In a mixing bowl, combine with 1 cup of brown sugar and ½ cup of granulated sugar, mixing well until smooth.

Add 2 eggs and 1 teaspoon of vanilla extract to the sugar mixture. Stir until fully incorporated. Combine 2¼ cups of flour, 1 teaspoon of baking soda, and ½ teaspoon of salt in a separate bowl, then add to the wet mixture until a soft dough forms.

Chop the cooled toffee into bite-sized pieces and gently fold into the cookie dough.

Scoop about 3 tablespoons of dough and place on a lined cookie sheet. Top each cookie with a sprinkle of flakey sea salt.

Allow dough to rest for about 10 minutes. Preheat your oven to 350°F (175°C) while the dough rests. Bake for 9-11 minutes until spread and not glossy in the center.