America's Test Kitchen Zucchini Bread Recipe: Moist Crumb With Walnut Swirls and Warm Spice

America's Test Kitchen zucchini bread recipe delivers the perfect balance of moist crumb and warm spice—a crowd-pleaser that bakes up tender, flavorful, and never dry. The walnut swirl adds a satisfying texture contrast while keeping the bread's signature comfort intact.

I've baked this version dozens of times, and it consistently outperforms boxed mixes with its rich, spiced flavor and perfect crumb.

What sets this recipe apart is the precise technique for achieving that signature moist texture without adding extra fat. The zucchini's natural moisture blends seamlessly with the spices and walnuts, while the baking soda ensures a light rise.

You'll need a standard loaf pan and basic mixing tools, but the process is straightforward—ideal for both beginners and experienced bakers.

The result is a loaf with a golden, crackly top, a tender crumb that's neither dense nor cakey, and pockets of caramelized walnuts throughout. Each slice delivers warm cinnamon, nutmeg, and allspice notes balanced by the subtle sweetness of the zucchini.

This is the kind of bread that disappears quickly from your counter.

For even more flavor, consider adding chocolate chips or extra nuts to the batter. The recipe scales perfectly for gifts or holiday baking, and leftovers stay fresh for days. Let's get started on making this foolproof zucchini bread that tastes like a bakery favorite.

Ingredients for america's test kitchen zucchini bread

Fifteen quality ingredients blend to create America's Test Kitchen's signature moist zucchini bread with walnut swirls.

The flour and sugars form the bread's structural backbone. King Arthur or Bob's Red Mill flours yield the best crumb texture, while Domino or Gold Medal work in a pinch. For sugars, Domino or C&H brands ensure consistent granulation. The zucchini's moisture is critical—use a microplane or box grater and squeeze out excess liquid with a clean kitchen towel. Walnuts should be raw and lightly toasted (350°F for 8-10 minutes) to develop their rich, caramelized flavor. Store nuts in an airtight container to prevent oxidation.

Substitutions must preserve moisture balance. Applesauce can replace half the zucchini (1 cup applesauce for 0.75 cups zucchini), but texture may slightly alter. For nutmeg, mace works at half the quantity though flavor differs. Corn syrup may be swapped with honey or maple syrup, but reduce other liquids by 0.125 cup to maintain moisture. If walnuts are unavailable, pecans or hazelnuts provide similar texture. For a gluten-free version, King Arthur Measure for Measure flour blend works well—adjust liquid by 0.25 cup less. Always sift dry ingredients to prevent dense crumb.

This loaf maintains peak freshness for 3 days at room temperature when wrapped tightly in plastic. For longer storage, freeze slices individually wrapped for up to 3 months—reheat in a 350°F oven for 5-7 minutes. The walnut swirl stays crisp when reheated briefly. For gifting, wrap cooled loaves in parchment paper and tie with twine. Leftovers can be toasted with butter and cinnamon sugar for a delightful treat. Store corn syrup in a cool, dark cabinet to prevent crystallization.

Step-by-step instructions for america's test kitchen zucchini bread

This method delivers a perfectly moist crumb with tender texture and warm spice notes throughout.

Begin by grating the 1.5 cups zucchini using the large holes of a box grater. Transfer the grated zucchini to a clean kitchen towel and squeeze firmly to remove excess moisture. This step is critical—wet zucchini makes the bread dense. In a dry skillet over medium heat, toast the 1 cup chopped walnuts for 3-4 minutes until fragrant and lightly golden. Let cool completely before using, as warm walnuts release oils that can make the dough greasy.

While the walnuts toast, measure out all your dry ingredients: 2.5 cups all-purpose flour, 2 teaspoons ground cinnamon, 0.5 teaspoon ground nutmeg, 0.5 teaspoon ground allspice, 0.5 teaspoon salt, and 1 teaspoon baking soda. Sift them together into a medium bowl to eliminate any lumps. This ensures even distribution throughout the batter and prevents dense pockets in your bread.

In a stand mixer fitted with the paddle attachment, beat the 1 cup unsalted butter (cold, cubed) with 1.5 cups granulated sugar and 0.5 cup packed brown sugar on medium speed for 3-4 minutes. The mixture should become light and fluffy, nearly doubling in volume. This creaming process incorporates air, which creates a tender crumb. Scrape down the sides of the bowl with a spatula to ensure even mixing.

Add the 2 whole large eggs one at a time, mixing just until each is fully incorporated. After the second egg, add the 1 tablespoon vanilla extract and mix for an additional 30 seconds. The batter should be smooth and pale in color. This step builds structure while keeping the finished bread moist—don't overmix or you'll develop gluten, leading to a tough texture.

Reduce the mixer speed to low and gradually add the sifted dry ingredients in three additions, mixing just until combined after each. After the final addition, fold in the squeezed zucchini and 0.25 cup light corn syrup using a spatula. The corn syrup acts as a moisture retainer, ensuring your bread stays tender for days. Mix until just combined—overmixing will activate the gluten and create a dense loaf.

Remove the bowl from the mixer and stir in the cooled, toasted walnuts. The dough will be thick and sticky, but that's exactly what we want for a moist crumb. If the dough seems too stiff, add 1 tablespoon milk (not listed in ingredients—use if needed) to help bind it. Fold in the walnuts gently to maintain their texture and prevent breaking.

Preheat your oven to 350°F and grease a 9x5-inch loaf pan with butter or line it with parchment paper. Spoon about half of the dough into the prepared pan and spread it evenly. Sprinkle half of the reserved walnuts over the top, then add the remaining dough and spread it evenly. Finally, sprinkle the remaining walnuts over the top, pressing down lightly to create a marbled effect.

Bake for 50-60 minutes, or until a toothpick inserted into the center comes out clean. The top should be golden brown, and the internal temperature should reach 205-210°F. If the top browns too quickly, tent the pan with foil. The bread is done when it springs back slightly when pressed in the center—this indicates proper doneness and moisture retention.

Remove the bread from the oven and let it cool in the pan for 10 minutes. Then transfer it to a wire rack to cool completely. This resting period allows the moisture to redistribute, resulting in a more even texture. Slice the bread while still slightly warm for the best experience—each piece should be moist with a tender crumb and pockets of warm spice.

Store any leftovers wrapped tightly in plastic at room temperature for up to 3 days, or freeze for up to 3 months. The corn syrup and zucchini combination keeps this bread moist even after baking, making it perfect for breakfast or as an afternoon snack with a spread of cream cheese or butter.

Storing and reheating this america's test kitchen zucchini bread

Room Temperature Storage

Wrap your cooled zucchini bread tightly in plastic wrap or place it in an airtight container to lock in moisture. Store it at room temperature for up to 3 days—the walnut swirl stays fresh and the spices retain their warmth.

I like using Saran Wrap for quick access or glass containers for longer storage. Keep it away from direct sunlight to prevent the crust from drying out prematurely. 💛

Refrigerator Refresh

If you need to extend freshness beyond 3 days, transfer the bread to the refrigerator where it’ll stay good for 5-7 days. The cold air preserves the moist crumb, but the texture may become slightly denser.

To revive, slice and warm in the microwave for 10-15 seconds or toast in a toaster oven at 350°F for 3-4 minutes. This works especially well for breakfast toast with butter or cream cheese.

Freezer-Friendly Slices

For long-term storage, slice the bread and wrap each piece individually in plastic wrap, then place them in a freezer bag with all air removed. This method prevents freezer burn and keeps the walnuts crisp.

Store for up to 3 months—when ready to eat, thaw at room temperature for 30 minutes or reheat directly from frozen in a 350°F oven for 5-7 minutes until warmed through. The corn syrup ensures the bread stays moist even after freezing. ❄️

Reviving Stale Bread

If your zucchini bread loses its moisture, don’t toss it! Slice and toast in a toaster oven at 375°F for 5-7 minutes with a light brushing of melted butter or a sprinkle of cinnamon sugar.

Alternatively, wrap the whole loaf in aluminum foil and warm in the oven at 300°F for 10 minutes—this restores the tender crumb. For a creative twist, blend stale slices into zucchini bread crumbs for breading or meatloaf mix-ins.

Gift-Worthy Packaging

When gifting, wrap the cooled loaf in parchment paper to protect the crust, then tie with twine and add a baker’s tag for a professional touch. Place in a gift box or cellophane bag for extra presentation.

The walnut swirl and warm spices make this bread a perfect hostess gift—it’s always a hit at holiday parties or potlucks. Store gifts in a cool, dark place until ready to serve to maintain freshness. 🎁

Frequently asked questions