Serves: Prep: 20min |Cook: 40min |Total: 2hr 0min
Heat oven to 350F. Coat 12-cup Bundt pan with cooking spray. Sift 2 1/4 cups all-purpose flour, 1 1/4 cups sugar, 1 Tbsp baking soda, and 1/4 tsp salt together in large bowl. Set aside. Whisk 1 cup applesauce, 3 lg eggs, 6 Tbsp safflower oil, and 1 Tbsp vanilla extract in medium bowl. Stir in dry ingredients until combined. Fold in 3 cups grated zucchini and 1 1/2 cups chopped toasted walnuts until incorporated. Pour into pan and bake until wooden pick inserted in center comes out clean, 40 to 45 minutes. Cool cake in pan 10 minutes, then remove and place on rack to cool. Place heatproof bowl over, but not touching, barely simmering water. Add 6 oz chopped bittersweet chocolate, 2 Tbsp unsalted butter, and 4 tsp whole milk. Stir until melted and smooth. Spoon glaze over cake and let set slightly before serving.