In a spacious bowl, whisk together the melted butter, brown sugar, white sugar, vanilla, orange zest, and eggs.
In a separate bowl, sift together the flour, cinnamon, baking soda, baking powder, and salt.
Add the dry mixture to the wet and blend thoroughly with a sturdy spoon.
Stir in the drained pineapple, zucchini, carrots, and walnuts.
Divide the batter evenly between the two prepared pans and bake in the middle of the preheated oven for about 50 minutes, until the loaves feel firm and springy when pressed in the center and a tester inserted comes out clean.
Serve slightly warm or at room temperature with Horizon Organic butter or cream cheese.
Loaves will keep well wrapped at room temperature for two days, in the refrigerator for five days, or in the freezer for up to four months.