Prepare the Oven and Pan: Preheat your oven to 350°F (175°C). Lightly grease a 9x13-inch baking dish or line it with parchment paper to ensure easy removal.

Cream the Butter and Sugar: In a large mixing bowl, beat the room-temperature butter and packed brown sugar together until creamy and fluffy, about 2-3 minutes.

Add the Wet Ingredients: Crack in the eggs one by one, beating thoroughly after each addition. Stir in the vanilla extract until fully incorporated.

Prepare the Dry Ingredients: In another bowl, whisk together the flour, baking powder, and salt. Slowly incorporate this dry mixture into the butter mixture, stirring gently until everything is well combined.

Fold in the Zucchini and Butterscotch Chips: Gently fold the finely grated and drained zucchini into the batter, followed by the butterscotch morsels. Ensure the ingredients are evenly distributed but avoid overmixing.

Bake the Bars: Transfer the batter into the prepared baking dish, smoothing it out evenly. Bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs.

Cool and Serve:

Let the bars cool completely in the pan before cutting them into slices. Cut into squares and enjoy!