Preheat the oven to 350°F (175°C) and line two baking sheets with parchment paper.

Cream the softened unsalted butter with granulated sugar using an electric mixer until light and fluffy, about 2-3 minutes.

Add the egg and vanilla extract to the mixture and mix until smooth and creamy.

Whisk together the flour, baking soda, baking powder, and salt in a separate bowl, then gradually add it to the wet mixture until just combined.

Fold in the toffee bits evenly throughout the dough.

Scoop portions of the dough, roll into balls, and coat each ball in granulated sugar before placing them on the baking sheets.

Bake for 10-12 minutes until edges are golden and tops appear crinkly.

Cool the cookies on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.