I tucked summer zucchini into a moist cinnamon-spiced crumb cake crowned with buttery brown sugar crumbs and sweet vanilla icing, and the result tastes like breakfast’s best kept secret.

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I am obsessed with this zucchini crumb cake because it sneaks summer into breakfast and refuses to be boring. I love the way the crumb topping collapses into tender cake, each bite flecked with finely shredded zucchini that somehow makes it moist without screaming vegetable.

Ground cinnamon threads through the batter, warm and honest, never cloying. But the best part is the contrast of crunchy topping and sweet drizzle and a glorious mess happens.

Pure indulgence and garden green. I will gladly eat a slice for dessert, for brunch, for no reason at all.

seriously, always. No regrets, truly always.

Ingredients

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All-purpose flour: basic structure, keeps the cake from collapsing.
Baking powder: light lift, makes it fluffy and soft.
Baking soda: reacts with acid, gives extra rise.
Salt: balances sweetness, makes flavors pop.
Cinnamon: warm spice note, cozy and familiar.
Nutmeg: subtle warmth, a little cozy depth.
Granulated sugar: sweetness and tender crumb.
Brown sugar: moistness and caramel-like depth.
Eggs: binder and protein, helps it set.
Vegetable oil: keeps it moist, not cakey.
Sour cream: tang and richness, makes it tender.
Vanilla extract: sweet perfume, soft background flavor.
Zucchini: adds moisture and sneaky veg goodness.
Crumb flour: gives the topping its sturdy bits.
Crumb brown sugar: sweet, sticky little crunchy pockets.
Crumb cinnamon: warmth in every crunchy bite.
Cold butter: creates flaky, buttery crumbs when cut in.
Pinch of salt: sharpens the crumb’s sweetness.
Powdered sugar: thin sweet glaze, bright finish.
Milk or cream: thins glaze to drippy perfection.
Glaze vanilla: rounds the glaze, adds soft aroma.

Ingredient Quantities

2 cups all purpose flour

1 1/2 teaspoons baking powder

1/2 teaspoon baking soda

1/2 teaspoon salt

1 teaspoon ground cinnamon

1/4 teaspoon ground nutmeg

1 cup granulated sugar

1/2 cup packed light brown sugar

2 large eggs

1/2 cup vegetable oil

1/2 cup sour cream

2 teaspoons vanilla extract

2 cups finely shredded zucchini, squeezed of excess moisture (about 2 medium zucchini)

For the crumb topping: 1 1/4 cups all purpose flour

For the crumb topping: 3/4 cup packed light brown sugar

For the crumb topping: 1 teaspoon ground cinnamon

For the crumb topping: 1/2 cup (1 stick) cold unsalted butter, cut into small pieces

Pinch of salt for the crumb

For the glaze: 1 cup powdered sugar

For the glaze: 1 to 2 tablespoons milk or cream

For the glaze: 1/2 teaspoon vanilla extract

How to Make this

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1. Preheat oven to 350F. Grease a 9×13 inch pan and line with parchment if you want easy removal later.

2. In a bowl whisk together 2 cups all purpose flour, 1 1/2 tsp baking powder, 1/2 tsp baking soda, 1/2 tsp salt, 1 tsp ground cinnamon and 1/4 tsp ground nutmeg.

3. In a large bowl beat 1 cup granulated sugar and 1/2 cup packed light brown sugar with 2 large eggs until smooth. Add 1/2 cup vegetable oil, 1/2 cup sour cream and 2 tsp vanilla extract and mix until combined.

4. Fold the dry ingredients into the wet mix just until mostly combined, dont overmix. Gently fold in 2 cups finely shredded zucchini that has been squeezed of excess moisture.

5. Spread the batter evenly into the prepared pan.

6. Make the crumb topping by mixing 1 1/4 cups all purpose flour, 3/4 cup packed light brown sugar, 1 tsp ground cinnamon and a pinch of salt. Cut in 1/2 cup (1 stick) cold unsalted butter with a pastry cutter or your fingers until mixture forms pea to breadcrumb sized clumps.

7. Sprinkle the crumb topping evenly over the batter, pressing a few crumbs down so they stick a bit but leaving lots of crumbly pieces.

8. Bake at 350F for about 35 to 40 minutes or until a toothpick inserted in the center comes out with a few moist crumbs but not wet batter. Let cake cool in the pan on a wire rack for at least 20 minutes.

9. While cake cools whisk together 1 cup powdered sugar, 1/2 tsp vanilla extract and 1 to 2 tbsp milk or cream until smooth and pourable. Adjust milk to get a drizzling consistency.

10. Drizzle the glaze over the warm but not hot cake, let set for a few minutes, slice and serve. Store any leftovers covered at room temp for 2 days or refrigerated up to 5 days.

Equipment Needed

1. Oven and 9×13 inch baking pan (grease it or line with parchment for easy removal)
2. Parchment paper (or nonstick spray if you dont have parchment)
3. Large mixing bowls (one for dry, one for wet)
4. Measuring cups and spoons
5. Electric mixer or a sturdy whisk and a wooden spoon (either works, mixer is faster)
6. Box grater for the zucchini and a clean kitchen towel or cheesecloth to squeeze out moisture
7. Pastry cutter or two forks (to cut the cold butter for the crumb topping)
8. Rubber spatula or offset spatula to spread the batter and press crumbs down a bit
9. Wire cooling rack and a toothpick for testing doneness (plus oven mitts)

FAQ

How do I stop the cake from getting soggy from the zucchini?

Squeeze the shredded zucchini in a clean dish towel or paper towels until most moisture is out. You want it damp, not dripping. Also make sure you measure the flour correctly by spooning it into the cup and leveling it, not scooping.

Can I replace the vegetable oil with something else?

Yes. You can use melted coconut oil or neutral-tasting melted butter in a 1 to 1 swap. If you use butter the cake will be a touch richer and might brown faster so keep an eye on it.

The crumb topping seems dry, how do I get big clumps instead of tiny crumbs?

Use very cold butter and cut it in with a pastry cutter or your fingers just until pea-sized bits form. Pressing some of the mixture together with your fingers before scattering it on the batter helps create larger clumps.

What oven temp and baking time should I use?

Bake at 350 F in a greased 9×13 or similar pan. It usually takes about 35 to 45 minutes. Start checking at 30 minutes; a toothpick in the center should come out with a few moist crumbs, not wet batter.

Can I make this ahead or freeze it?

Yes. The cake keeps well in an airtight container for 2 to 3 days at room temp, or up to a week in the fridge. Freeze unfrosted slices for up to 3 months, then thaw and drizzle glaze before serving.

How do I get the glaze right so it isn't too runny or too thick?

Start with 1 tablespoon of milk or cream and whisk into the powdered sugar and vanilla. Add the second tablespoon only if needed. It should coat a spoon and slowly run off. If it gets too thin add a bit more powdered sugar.

Zucchini Crumb Cake Recipe Substitutions and Variations

All purpose flour: swap with whole wheat pastry flour, 1 to 1. It makes the cake nuttier and still tender. If you need gluten free use a 1 to 1 GF baking blend instead, no extra xanthan usually required.
Vegetable oil: use melted coconut oil, equal amount, for a subtle coconut flavor. Or use unsweetened applesauce but only replace half the oil with applesauce (so 1/4 cup applesauce + 1/4 cup oil) otherwise the crumb can get gummy.
Sour cream: plain Greek yogurt works great, same amount. It gives the same tang and moisture, just don’t use fat free yogurt or the texture will be a bit thinner.
Crumb butter (cold unsalted butter): swap with chilled solid coconut oil or a vegan stick butter, cut into pieces the same way. Keep it cold so the crumbs stay chunky and not pastey.

Pro Tips

1. Squeeze the zucchini well, like really squeeze it in a clean towel or cheesecloth. If it still feels damp the crumb topping can go soggy and the cake texture will be gummy. You want it moist, not wet.

2. Use room temperature eggs and sour cream so they mix easier. Cold ingredients make the batter look lumpy and you might be tempted to overmix which makes the cake tough.

3. Chill the butter for the crumb and cut it into small pieces right before you mix. If the butter gets too warm the crumbs will melt into the batter instead of staying flaky and crunchy.

4. Bake toward the lower end of the time if your oven runs hot and check with toothpick in a few spots. The crumb can brown faster than the center cooks, so tent loosely with foil for the last 10 minutes if the top is getting dark.

Zucchini Crumb Cake Recipe

Recipe by Tina Bueller

0.0 from 0 votes

I tucked summer zucchini into a moist cinnamon-spiced crumb cake crowned with buttery brown sugar crumbs and sweet vanilla icing, and the result tastes like breakfast's best kept secret.

Servings

servings

Calories

510

kcal

Equipment: 1. Oven and 9×13 inch baking pan (grease it or line with parchment for easy removal)
2. Parchment paper (or nonstick spray if you dont have parchment)
3. Large mixing bowls (one for dry, one for wet)
4. Measuring cups and spoons
5. Electric mixer or a sturdy whisk and a wooden spoon (either works, mixer is faster)
6. Box grater for the zucchini and a clean kitchen towel or cheesecloth to squeeze out moisture
7. Pastry cutter or two forks (to cut the cold butter for the crumb topping)
8. Rubber spatula or offset spatula to spread the batter and press crumbs down a bit
9. Wire cooling rack and a toothpick for testing doneness (plus oven mitts)

Ingredients

2 cups all purpose flour
1 1/2 teaspoons baking powder
1/2 teaspoon baking soda
1/2 teaspoon salt
1 teaspoon ground cinnamon
1/4 teaspoon ground nutmeg
1 cup granulated sugar
1/2 cup packed light brown sugar
2 large eggs
1/2 cup vegetable oil
1/2 cup sour cream
2 teaspoons vanilla extract
2 cups finely shredded zucchini, squeezed of excess moisture (about 2 medium zucchini)
For the crumb topping: 1 1/4 cups all purpose flour
For the crumb topping: 3/4 cup packed light brown sugar
For the crumb topping: 1 teaspoon ground cinnamon
For the crumb topping: 1/2 cup (1 stick) cold unsalted butter, cut into small pieces
Pinch of salt for the crumb
For the glaze: 1 cup powdered sugar
For the glaze: 1 to 2 tablespoons milk or cream
For the glaze: 1/2 teaspoon vanilla extract

Directions

Preheat oven to 350F. Grease a 9×13 inch pan and line with parchment if you want easy removal later.
In a bowl whisk together 2 cups all purpose flour, 1 1/2 tsp baking powder, 1/2 tsp baking soda, 1/2 tsp salt, 1 tsp ground cinnamon and 1/4 tsp ground nutmeg.
In a large bowl beat 1 cup granulated sugar and 1/2 cup packed light brown sugar with 2 large eggs until smooth. Add 1/2 cup vegetable oil, 1/2 cup sour cream and 2 tsp vanilla extract and mix until combined.
Fold the dry ingredients into the wet mix just until mostly combined, dont overmix. Gently fold in 2 cups finely shredded zucchini that has been squeezed of excess moisture.
Spread the batter evenly into the prepared pan.
Make the crumb topping by mixing 1 1/4 cups all purpose flour, 3/4 cup packed light brown sugar, 1 tsp ground cinnamon and a pinch of salt. Cut in 1/2 cup (1 stick) cold unsalted butter with a pastry cutter or your fingers until mixture forms pea to breadcrumb sized clumps.
Sprinkle the crumb topping evenly over the batter, pressing a few crumbs down so they stick a bit but leaving lots of crumbly pieces.
Bake at 350F for about 35 to 40 minutes or until a toothpick inserted in the center comes out with a few moist crumbs but not wet batter. Let cake cool in the pan on a wire rack for at least 20 minutes.
While cake cools whisk together 1 cup powdered sugar, 1/2 tsp vanilla extract and 1 to 2 tbsp milk or cream until smooth and pourable. Adjust milk to get a drizzling consistency.
Drizzle the glaze over the warm but not hot cake, let set for a few minutes, slice and serve. Store any leftovers covered at room temp for 2 days or refrigerated up to 5 days.

Notes

Below you’ll find my best estimate of this recipe’s nutrition facts. Treat the numbers as a guide rather than a rule—great food should nourish both body and spirit. Figures are approximate, and the website owner assumes no liability for any inaccuracies in this recipe.