Preheat your oven to 375°F (190°C). Line two large baking sheets with parchment or silicone liners.
In a medium bowl, whisk together the flour, baking soda, baking powder, salt, cinnamon, and cardamom. Set aside.
In the bowl of a stand mixer, combine softened butter, both sugars, and molasses. Beat until light, about 1–2 minutes.
Add eggs and vanilla to the butter mix. Beat for 1 minute, scraping down the sides.
Add dry ingredients to wet mixture and mix on low until just blended. Avoid overmixing.
Add oats and butterscotch chips. Mix on low only until combined.
Cover and refrigerate dough for at least 1 hour. This step is key for chewy cookies.
Scoop out balls of dough (about 1.5 to 2 tablespoons each) and space them out on the baking sheets.
Bake one tray at a time for 12–13 minutes, until tops are just turning golden and edges are set. Centers may look slightly underbaked—they will firm up as they cool.
Let cookies rest on the pan for 5 minutes before moving to a wire rack to finish cooling.
Notes
Quick oats can be substituted for old-fashioned, but the refrigeration time becomes critical if you want a chewy cookie, rather than a cakey texture.Molasses is optional, but I find it deepens the flavor.Nuts are often added. Chopped pecans are a good choice. 1 cup is the usual amount.