Preheat the oven to 350°F. Use a pastry brush to grease a 9-inch loaf pan with 1½ teaspoons of the olive oil, and line the bottom with parchment paper. Set aside.

In a medium-sized mixing bowl, combine the flour, baking powder, baking soda, cinnamon, allspice and salt. Set aside.

In another bowl, combine the olive oil, sugar, mashed avocado, and vanilla. Use a whisk or a fork to mix it until it's very smooth. Add the eggs and mix until they are completely blended in. Then fold in the grated zucchini and combine.

Now add the dry mixture to the wet mixture and stir only long enough to combine.

Pour the batter in the prepared pan and bake in the preheated 350°F oven until the top is golden brown, and beginning to crack, about 1 hour.

Let the bread cool in the pan for about 15 minutes. Use a dull knife to go around the edges of the bread to ensure it's loose, and then invert bread onto a cooling rack. Genlty turn it over and continue to cool for about 15 more mintues before serving.