Preheat your oven to 350°F. Spray a 9x13 pan with non-stick spray or butter and flour it.

In a large bowl, cream together the butter and brown sugar with a hand mixer until it's light and fluffy.

Add the eggs and vanilla to the butter mixture and mix until fully combined, about 1-2 minutes. Scrape down the bowl as needed.

Add the flour, baking powder, and salt to the bowl and mix on medium-low until just combined.

Mix in the zucchini on low. The mixture should be runny. If it seems dry, let it sit for 5 minutes.

Stir in 1 cup of butterscotch morsels with a spatula.

Pour the batter into the prepared pan and sprinkle the remaining butterscotch morsels on top.

Bake for 40 minutes. Check for doneness by inserting a toothpick, which should come out with a few crumbs but no wet batter. The top should be dark, and the edges should look well-baked.