01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together the gluten-free flour, baking soda, baking powder, and salt. Set aside.
03 - In a large bowl, cream the softened butter with brown sugar and granulated sugar until light and fluffy, about 2 minutes.
04 - Beat in the eggs one at a time, then add vanilla extract and mix until combined.
05 - Gradually add the dry ingredients to the wet mixture, mixing until just combined.
06 - Fold in the dark chocolate chunks and toffee bits using a spatula.
07 - Scoop tablespoon-sized portions of dough onto prepared baking sheets, spacing about 2 inches apart.
08 - Bake for 10–12 minutes, or until the edges are golden and the centers are set.
09 - Allow cookies to cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.