Preheat your oven: Set oven to 350°F (175°C) and line baking sheets with parchment paper.
Cream the butter and sugars: In a large bowl, beat together the softened butter, brown sugar, and granulated sugar until light and fluffy (about 2–3 minutes).
Add eggs and vanilla: Beat in the eggs one at a time, ensuring each is fully incorporated. Stir in the vanilla extract.
Mix the dry ingredients: In a separate bowl, whisk together the flour, baking soda, and salt. Gradually add the dry ingredients to the butter mixture, mixing until just combined.
Fold in oats and toffee: Stir in the oats and toffee bits until evenly distributed throughout the dough. Avoid overmixing to keep the cookies tender.
Scoop and top: Drop rounded tablespoons of dough onto prepared baking sheets, spacing each about 2 inches apart. Sprinkle a small pinch of sea salt on top of each dough mound.
Bake: Bake for 10–12 minutes, or until edges are golden brown and centers still look soft. They will continue to firm up as they cool.
Cool: Let the cookies cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.
