Preheat your oven to 350°F (175°C). This will ensure your cookies bake evenly and get that delightful golden brown color.
In a medium bowl, whisk together the all-purpose flour, sea salt, baking soda, and baking powder. Set this mixture aside for later.
In a large mixing bowl, use an electric mixer to cream together the room temperature unsalted butter, granulated sugar, and packed light brown sugar until the mixture is light and fluffy, about 3-4 minutes.
Add the two large eggs, one at a time, mixing well after each addition. Then, pour in the two teaspoons of vanilla extract and mix until fully incorporated.
Gradually add the dry ingredient mixture into the wet ingredients, mixing on low speed until just combined. Be careful not to overmix; you want a soft dough.
Using a spatula, gently fold in the semi-sweet chocolate chips, chopped hazelnuts, and Heath toffee bits until evenly distributed throughout the dough.
Using a cookie scoop, drop rounded tablespoons of dough onto a baking sheet lined with parchment paper. Leave enough space between each cookie as they will spread while baking. Sprinkle a little extra sea salt on top of each cookie.
Place the cookie sheet in the preheated oven and bake for 10-12 minutes, or until the edges are lightly golden. The centers may look slightly underbaked, but they will continue to firm up as they cool.
Remove the cookies from the oven and allow them to cool on the baking sheet for about 5 minutes before transferring them to a cooling rack. Once cooled, enjoy your delicious Hazelnut Toffee Chocolate Chip Cookies with a glass of milk or your favorite beverage!