6-Inch Apple Cake Recipe: Single-Serve Spice Cake With Buttery Streusel Top

This 6-inch apple cake recipe delivers all the cozy, spiced apple flavor of a traditional cake in a perfect single-serving size. 🍏 The secret lies in a tender crumb base infused with cinnamon and nutmeg, topped with a buttery streusel that caramelizes beautifully in the oven. I developed this recipe after years of baking full-size apple cakes—now you can enjoy the same comforting flavors without the leftovers. The beauty of this mini cake is its simplicity: just six ingredients for the cake batter and four for the streusel topping. The cake bakes in 30 minutes at 350°F, yielding a moist, lightly spiced crumb that practically melts in your mouth. The streusel topping adds a delightful crunch contrast while keeping the cake's edges perfectly golden. What makes this recipe truly special is how it balances tradition with convenience. The spices—cinnamon, nutmeg, and allspice—create that classic apple cake warmth, while the streusel adds texture without overwhelming the delicate cake. It's the ideal dessert for a quiet afternoon, a coffee break, or a thoughtful single serving. Perfect for meal prep or last-minute cravings, this cake keeps well at room temperature for two days or can be frozen for up to a month. Serve warm with a scoop of vanilla ice cream or a dollop of whipped cream for the ultimate indulgence. Let's get baking!

Ingredients for 6 inch apple cake

Six simple ingredients for the cake, four for the streusel—just enough to make this cozy apple cake perfect for one.

The apples are everything here. Granny Smith or Honeycrisp work best—they hold their shape and stay tart after baking. I always buy them a day ahead and let them sit at room temperature (they get sweeter!). If you can't find fresh, unsweetened applesauce at half the amount works in a pinch, but nothing beats the real thing. For the flour, King Arthur or Bob's Red Mill are my go-tos—they bake up light and tender. And that butter? Use Land O'Lakes or Plugrá—they're reliable for baking. If you're feeling fancy, swap the walnuts for pecans or hazelnuts for a different crunch.

No vanilla extract? Vanilla sugar at double the amount gets you close. Running low on cinnamon? Cassia cinnamon works too, but it's stronger, so start with half. The streusel can be made ahead—just store it in the fridge until ready to bake. For a gluten-free version, swap the flour for a 1:1 gluten-free blend (like Bob's Red Mill), but add an extra 0.25 cup to account for less binding. The oats? Quick oats work too, but rolled oats give that perfect crumbly texture. And if you're using a 6-inch springform pan, grease it well—this cake sticks to nothing!

The cake keeps beautifully at room temperature for 2 days in an airtight container, but honestly, it's best the day it's made. For longer storage, freeze the whole cake (unfrosted) for up to 1 month3 days ahead and stored in the fridge. Serve warm with a scoop of vanilla ice cream or a dollop of Cool Whip for that classic dessert vibe. Leftovers? Reheat in the microwave for 10-15 seconds to bring back that fresh-baked magic.

Step-by-step instructions for single-serve apple cake

This perfect 6-inch cake delivers moist spice cake with a buttery streusel top—every bite is pure comfort.

Start by peeling and dicing the 0.75 cup apples into ¼-inch cubes. I like to use a tart variety like Granny Smith—they hold up better during baking and add a nice tang. Toss the diced apples with 1 teaspoon granulated sugar and let them sit while you prep the rest. This jumpstarts their flavor and prevents them from sinking to the bottom.

Preheat your oven to 350°F and lightly grease a 6-inch round cake pan with butter or line it with parchment paper. I always use parchment for easy removal—no scrubbing required later. Place the pan on a baking sheet to catch any drips from the streusel topping.

In a small bowl, mix together the 0.25 cup old-fashioned rolled oats, 0.25 cup light brown sugar, 0.25 cup chopped walnuts, 1.5 teaspoons ground cinnamon, 0.25 teaspoon ground nutmeg, and 0.25 teaspoon allspice. Then cut in the 0.5 cup cold unsalted butter using a pastry cutter or your fingers until the mixture resembles coarse crumbs with some pea-sized butter pieces remaining. This texture is key—it should look like wet sand.

Spread about half of this streusel mixture evenly over the bottom of your prepared cake pan. This creates a flavorful base that prevents the cake from sticking and adds that signature crunchy contrast. Don't press it down—just let it settle naturally. Set the pan aside while you make the cake batter.

In a medium bowl, sift together the 0.75 cup all-purpose flour, 0.5 cup granulated sugar, 0.25 teaspoon salt, 1.5 teaspoons ground cinnamon, 0.25 teaspoon ground nutmeg, and 0.25 teaspoon allspice. Whisk until evenly distributed—this prevents lumps in your final cake. In a separate bowl, beat the 1 whole large egg and 1 teaspoon vanilla extract until just combined.

Add the wet ingredients to the dry ingredients and mix on low speed until just combined. Be careful not to overmix—you should still see some flour streaks. Fold in the prepared 0.75 cup diced apples with their juices using a spatula. The batter will be thick but pourable. Pour it over the streusel layer in the pan, spreading it evenly.

Sprinkle the remaining streusel mixture evenly over the top of the cake batter. Press down very lightly with your fingers—just enough to make it stick together. This creates that beautiful crumbly texture we all love. Dust the top with 1 tablespoon powdered sugar for a pretty finish and to help the streusel caramelize slightly.

Bake for 35-40 minutes until the top is deep golden brown and a toothpick inserted in the center comes out clean. The cake is done when the edges pull away slightly from the pan and the streusel looks toasted. If the top browns too quickly, tent loosely with foil after 20 minutes to prevent over-browning.

Let the cake cool in the pan for 10 minutes before carefully transferring it to a wire rack. The residual heat will help set the cake while it cools. Serve warm for the best texture—this is when the streusel is perfectly crisp and the cake is most tender. I like to slice it into 6 wedges for easy single-serving portions.

Each bite delivers moist spice cake with bursts of juicy apple and that irresistible buttery crunch from the streusel. The nutmeg and allspice add depth that makes this cake feel special—like a hug in dessert form. Store leftovers at room temperature for up to 3 days or refrigerate for up to 5 days, though I doubt it'll last that long!

Health benefits of these flavors

Fiber-Rich Apple Goodness

The diced apples in this cake provide a surprising 3 grams of fiber per serving, supporting healthy digestion and keeping you full longer. Using Granny Smith apples adds an extra tang that balances the sweetness while delivering soluble fiber that feeds your gut bacteria. 🍏

Warm Spices for Comfort

The combination of cinnamon, nutmeg, and allspice creates a cozy spice profile that boosts circulation and metabolism. Cinnamon helps regulate blood sugar, while nutmeg contains myristicin, a compound that may enhance cognitive function. Just 1.5 teaspoons of cinnamon in this recipe provides about 10% of your daily manganese needs.

Healthy Fats from Walnuts

The 0.25 cup chopped walnuts in the streusel add 4 grams of plant-based omega-3 fatty acids, which support heart health and reduce inflammation. Walnuts also provide 4 grams of protein per serving, making this cake more satisfying than traditional desserts. I always toast mine first to enhance their nutty flavor and antioxidant content.

Protein for Balance

While this is a dessert, the 1 whole egg in the batter contributes 6 grams of complete protein, helping stabilize blood sugar levels. The egg also creates a tender crumb that makes every bite satisfying. For an extra protein boost, consider adding 1 tablespoon Greek yogurt to the batter when mixing.

Antioxidant Boost

The apples and cinnamon combo provides powerful antioxidants like quercetin and polyphenols that combat oxidative stress. Cinnamon alone contains 12% of your daily antioxidant needs per teaspoon. This makes the cake not just delicious, but also a smart choice for your wellness routine. The walnuts add another layer of antioxidants with their high polyphenol content.

Portion Control Perfection

At just 6 inches wide, this single-serving cake makes indulgence guilt-free. The controlled portion size prevents overeating while still delivering all the comforting flavors of a traditional apple cake. It's the perfect balance of satisfaction and moderation—ideal for dessert lovers watching their portions. 💛

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