Chocolate Zucchini Brownie Cake

Bahan-bahan (18 porsi)

• 1 cup (2 sticks) butter, (at room temperature)
• 1½ cups granulated white sugar
• 2 large eggs, (at room temperature)
• ½ cup plain yogurt
• 1 teaspoon vanilla extract
• 2½ cups all purpose flour
• ¼ cup unsweetened cocoa powder
• 1 teaspoon baking soda
• ½ teaspoon salt
• 2 cups shredded zucchini
• 6 tablespoons butter, (at room temperature)
• 2⅔ cups powdered sugar
• ½ cup unsweetened cocoa powder
• 1 teaspoon vanilla extract
• ¼ to ⅓ cup 2% milk