Preheat the oven to 350 degrees and set out butter and gather all ingredients.
In a large bowl, beat butter, brown sugar, sugar, vanilla and corn syrup together until creamy.
Add eggs and beat until combined.
In a medium bowl, whisk flour, baking soda, baking powder and salt together.
Add dry ingredients into the wet ingredients mixture.
Stir in dark chocolate chunks and toffee bits.
Drop by rounded teaspoon, or 1 inch cookie scoop, onto an ungreased baking sheet or baking sheet lined with parchment paper.
Bake for 9-11 minutes or until the edges start to brown.
Remove from the oven and let cookies sit on the baking sheet for a couple minutes then transfer to a wire rack to cool.