Preheat your oven to 350°F (175°C).
In a medium bowl, whisk together the all-purpose flour, baking soda, and salt.
In a large mixing bowl, cream together the room-temperature unsalted butter, granulated sugar, and light brown sugar until light and fluffy, about 2-3 minutes.
Add the egg and vanilla extract to the butter-sugar mixture and beat until combined.
Gradually add the dry ingredient mixture to the wet ingredients, mixing on low speed until just combined.
Fold in the semisweet chocolate chips and coarsely chopped English toffee until evenly distributed.
Drop rounded tablespoons of dough onto baking sheets lined with parchment paper, spacing them about 2 inches apart.
Bake for 10-12 minutes or until the edges are lightly golden, but the centers are still soft.
Let the cookies cool on the baking sheets for 5 minutes before transferring them to a wire cooling rack.
