In a large mixing bowl, beat the softened butter and shortening together using an electric mixer until the mixture is light and fluffy, about 2-3 minutes.

Stir in the packed brown sugar until creamy, then add the eggs and vanilla extract. Beat until everything is well combined and the mixture is light in color, approximately 1 more minute.

In a separate bowl, whisk together the oats, flour, baking soda, baking powder, cinnamon, and salt.

Gradually incorporate the dry ingredients into the wet ingredients, doing this in three additions, stirring until just combined.

Gently fold in the toffee bits. Cover the bowl and refrigerate the dough for at least 30 minutes.

Preheat your oven to 350°F (175°C) while the dough chills. Prepare a baking sheet lined with parchment paper or a silicone mat.

Once the dough is chilled, scoop out tablespoon-sized balls and place them about 3 inches apart on the baking sheet.

Bake for 13-15 minutes, or until the edges are golden brown while the centers remain light in color.

Allow the cookies to cool on the tray for about 5 minutes before transferring them to a cooling rack to finish cooling.