Grease and flour a 9x13 baking dish. Preheat the oven to 325 degrees Fahrenheit.

In a large mixing bowl, combine all-purpose flour, whole wheat flour, baking powder, cinnamon, nutmeg, allspice, brown sugar, white sugar, and a pinch of salt.

In a separate medium bowl, mix the egg, canola oil, yogurt, buttermilk, vanilla, orange zest or juice, strained pineapple, coconut, shredded carrots, shredded zucchini, and chopped pecans.

Combine the wet ingredients with the dry ingredients and stir until just combined. Pour the batter into the prepared baking dish.

Bake for 50-60 minutes or until a toothpick inserted into the center comes out clean.

In a medium saucepan over medium-high heat, combine the ingredients for the cake syrup (white sugar, brown sugar, butter, buttermilk, and vanilla).

Cook, stirring occasionally, until the sugar is dissolved, and the syrup has thickened. Set aside.

While the cake is still hot, use the end of a butter knife to poke holes all over the top.

Pour the prepared cake syrup slowly over the hot cake, allowing it to soak in. Set aside to cool slightly.

In the bowl of an electric mixer fitted with a paddle attachment, combine softened cream cheese, butter, and vanilla extract. Mix until smooth and free of lumps.

Gradually mix in the powdered sugar until well combined.

Once the cake has cooled, frost it with the cream cheese frosting.

Refrigerate the cake for about 1 hour to let the frosting set.

Optionally, garnish with pecans or a sprinkle of cinnamon or nutmeg before serving.

Store the cake covered with plastic wrap in the refrigerator for up to two weeks.

Enjoy this moist and flavorful Carrot Cake with the perfect balance of sweetness from the buttermilk syrup and creaminess from the cream cheese frosting.