In a large bowl, combine the room temperature butter and shortening. Using an electric mixer, beat for about 2-3 minutes until the mixture becomes fluffy.

Gradually add in the brown sugar, then incorporate the eggs and vanilla extract. Continue to mix until everything is well-combined, scraping down the sides of the bowl as needed. You want a light color and a creamy texture, which should take about one more minute of mixing at medium-high speed.

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

Gradually mix the dry ingredients into the wet mixture in three separate additions. Be careful not to over-mix; you just want everything integrated.

Gently stir in the toffee bits. Cover the bowl and refrigerate the dough for 30 minutes.

Preheat your oven to 350 degrees F while the dough chills. Line a baking sheet with parchment paper or a silicone baking mat.

After the dough has chilled, scoop out tablespoon-sized balls of dough and place them on the prepared baking sheet, spacing them about 3 inches apart, as they will spread.

Bake in the preheated oven for 13-15 minutes. Look for golden brown edges, leaving the middles slightly lighter if you prefer a chewy cookie.

Remove the tray from the oven and let the cookies cool for about 5 minutes before transferring them to a cooling rack.