Quick Recipe Version (TL;DR)
Quick Ingredients
- 2 cups (250 g) all-purpose flour
- 1 tsp baking powder, 1/2 tsp baking soda, 1/2 tsp fine salt
- 1 1/2 tsp ground cinnamon + pinch nutmeg
- 1/2 cup (115 g) unsalted butter, softened
- 1/2 cup (120 ml) neutral oil (canola or vegetable)
- 1 cup (200 g) granulated sugar + 1/2 cup (110 g) packed light brown sugar
- 3 large eggs, 2 tsp vanilla extract
- 1 cup (240 ml) sour cream, room temperature
- 2 1/2 cups diced baking apples (2–3 medium), 1 tbsp lemon juice
- Streusel: 3/4 cup brown sugar, 1/2 cup flour, 1 1/2 tsp cinnamon, 1/4 tsp salt, 4 tbsp melted butter, 3/4 cup chopped walnuts
- Optional glaze: 3/4 cup powdered sugar, 1–2 tbsp milk or cream, 1/2 tsp vanilla
Do This
- 1. Heat oven to 350°F (175°C). Grease and line a 9×13-inch pan. Peel, core, and dice apples; toss with lemon juice.
- 2. Stir together streusel ingredients until clumpy; set aside.
- 3. Whisk flour, baking powder, baking soda, salt, cinnamon, and nutmeg in a bowl.
- 4. Beat butter, oil, sugars, and vanilla until fluffy. Beat in eggs one at a time, then mix in sour cream.
- 5. Gently mix dry ingredients into wet just until combined, then fold in diced apples.
- 6. Spread half the batter in the pan, sprinkle with half the streusel, top with remaining batter, then remaining streusel. Swirl lightly with a knife.
- 7. Bake 40–45 minutes, until a tester comes out clean. Cool, drizzle with glaze if using, slice, and serve.
Why You’ll Love This Recipe
- Moist, tender crumb thanks to sour cream, with warm cinnamon woven throughout.
- Plenty of real apple pieces in every bite plus a generous walnut streusel swirl and topping.
- Perfect for brunch, holidays, potlucks, or cozy afternoon coffee breaks.
- Uses simple pantry ingredients and can be made a day ahead with great results.
Grocery List
- Produce: 2–3 medium baking apples (such as Honeycrisp, Granny Smith, Braeburn, or Fuji), 1 lemon (optional, for the apples).
- Dairy: Unsalted butter, sour cream, milk or cream (for glaze, optional), 3 large eggs.
- Pantry: All-purpose flour, granulated sugar, light brown sugar, powdered sugar, baking powder, baking soda, fine salt, ground cinnamon, ground nutmeg, vanilla extract, neutral oil (canola or vegetable), walnuts, nonstick spray or extra butter for greasing the pan, parchment paper (optional but helpful).
Full Ingredients
For the Cinnamon–Walnut Streusel Swirl
- 3/4 cup (150 g) packed light brown sugar
- 1/2 cup (65 g) all-purpose flour
- 1 1/2 tsp ground cinnamon
- 1/4 tsp fine salt
- 4 tbsp (56 g) unsalted butter, melted and slightly cooled
- 3/4 cup (75 g) chopped walnuts (lightly toasted if you like extra flavor)
For the Apple Layer
- 2–3 medium firm baking apples (about 2 1/2 cups diced; 300–325 g peeled weight)
- 1 tbsp lemon juice (optional, to keep apples bright)
- 1 tbsp granulated sugar
- 1/2 tsp ground cinnamon
For the Coffee Cake Batter
- 2 cups (250 g) all-purpose flour
- 1 tsp baking powder
- 1/2 tsp baking soda
- 1/2 tsp fine sea salt
- 1 tsp ground cinnamon
- 1/4 tsp ground nutmeg (optional but lovely)
- 1/2 cup (115 g) unsalted butter, softened to room temperature
- 1/2 cup (120 ml) neutral oil (such as canola or vegetable oil)
- 1 cup (200 g) granulated sugar
- 1/2 cup (110 g) packed light brown sugar
- 3 large eggs, at room temperature
- 2 tsp vanilla extract
- 1 cup (240 ml) sour cream, at room temperature (full-fat or 14–18% preferred)
Optional Vanilla Glaze
- 3/4 cup (90 g) powdered sugar, sifted
- 1–2 tbsp milk or cream (start with 1 tbsp, add more as needed)
- 1/2 tsp vanilla extract
Step-by-Step Instructions
Step 1: Prepare the pan, oven, and apples
Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking pan with butter or nonstick spray. For easy removal and clean slices, line the bottom with parchment paper, letting it overhang on two sides like handles, then lightly grease the parchment as well.
Peel, core, and dice the apples into small 1/2-inch cubes so they soften nicely but still hold their shape. You should end up with about 2 1/2 cups of diced apple. Place them in a bowl, toss with the lemon juice (if using), granulated sugar, and cinnamon. Set aside while you prepare the streusel and batter; the apples will release a little juice and get lightly flavored.
Step 2: Make the cinnamon–walnut streusel
In a medium bowl, combine the brown sugar, flour, cinnamon, and salt. Stir with a fork until everything is evenly mixed and no streaks of flour remain. Pour in the melted, slightly cooled butter and stir until the mixture looks evenly moistened and forms clumps when you press it together.
Add the chopped walnuts and fold them in until they are well distributed. The streusel should be sandy with some larger, soft clumps—that texture will bake into crunchy, craggy pockets on top of the cake and a sweet swirl inside. Set the bowl aside.
Step 3: Whisk together the dry ingredients
In a separate medium bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon, and nutmeg until well combined. This step helps evenly distribute the leaveners and spices so you do not overmix the batter later.
Set the dry mixture aside; you will add it to the wet ingredients in a moment.
Step 4: Cream the butter, oil, and sugars
In a large mixing bowl (or the bowl of a stand mixer fitted with the paddle attachment), combine the softened butter, neutral oil, granulated sugar, and brown sugar. Beat on medium-high speed for 3–4 minutes, scraping down the bowl once or twice, until the mixture is noticeably lighter in color and looks fluffy. This step traps air and helps create a soft, tender crumb.
Add the vanilla extract, then beat in the eggs one at a time, fully incorporating each before adding the next. Scrape the bowl as needed. Mix in the sour cream on low speed just until smooth. The mixture may look slightly thick and creamy—that is perfect.
Step 5: Finish the batter and fold in the apples
Add the dry ingredient mixture to the wet ingredients in two additions, mixing on low speed just until no dry streaks of flour remain. Avoid overmixing at this stage; as soon as the flour is incorporated, stop. The batter will be thick, almost like a very soft cookie dough rather than pourable cake batter.
Using a spatula, gently fold the cinnamon-sugar apples (along with any juices in the bowl) into the batter until they are evenly distributed. Work slowly so you do not deflate the batter. You are now ready to assemble the cake layers.
Step 6: Assemble the layers and swirl the streusel
Spread about half of the batter evenly into the prepared 9×13-inch pan. Because the batter is thick, it helps to dollop it across the bottom in several spoonfuls, then gently spread it with an offset spatula or the back of a spoon into an even layer, reaching all the corners.
Sprinkle half of the streusel mixture evenly over this first layer of batter. Dollop the remaining batter over the streusel in small mounds, then carefully spread it out as evenly as you can. It is fine if some streusel peeks through. Top with the remaining streusel in an even layer. Use a butter knife to gently swirl through the batter and streusel a few times, creating loose “S” shapes—do not over-swirl, or the layers will completely blend.
Step 7: Bake, cool, and glaze
Transfer the pan to the preheated oven and bake for 40–45 minutes, rotating the pan halfway through baking. The coffee cake is done when the top is golden brown, the streusel smells deeply toasty, and a toothpick inserted into the center comes out mostly clean with a few moist crumbs (but no wet batter).
Place the pan on a wire rack and let the cake cool at least 25–30 minutes. If using the parchment sling, run a knife around the uncovered edges, then lift the cake out to cool completely before glazing and slicing.
For the optional vanilla glaze, whisk together the powdered sugar, 1 tbsp of milk or cream, and vanilla until smooth. Add more milk a few drops at a time until the glaze is thick but runs in a ribbon off the spoon. Drizzle over the cooled or slightly warm cake in zigzags. Slice into 12 squares and serve warm or at room temperature.
Pro Tips
- Use firm baking apples. Varieties like Honeycrisp, Granny Smith, Braeburn, or Fuji hold their shape and provide a pleasant sweet-tart contrast.
- Room-temperature ingredients matter. Soft butter, room-temperature eggs, and sour cream blend more smoothly and help the cake rise evenly.
- Do not overmix once you add the flour. Overmixing develops gluten and can make the cake dense. Mix just until no dry streaks remain.
- Pan choice affects baking time. A light-colored metal pan bakes most evenly. Dark metal may bake faster; start checking a few minutes early.
- Resist over-swirl temptation. A few gentle passes with a knife are enough; leaving visible layers gives you pretty marbling and distinct pockets of streusel.
Variations
- Pecan or hazelnut streusel: Swap the walnuts for chopped pecans or hazelnuts for a different nutty aroma and texture.
- Apple–pear coffee cake: Use a mix of diced apples and ripe but firm pears for a more delicate, aromatic fruit layer.
- Maple glaze: Replace part of the milk in the glaze with pure maple syrup and reduce the powdered sugar slightly for a warmly flavored finish.
Storage & Make-Ahead
Once completely cooled, cover the coffee cake tightly with foil or transfer slices to an airtight container. Store at room temperature for up to 3 days, or in the refrigerator for up to 5 days. For longer storage, wrap individual slices in plastic wrap, then place in a freezer bag and freeze for up to 2 months. Thaw at room temperature or warm gently in a low oven (300°F / 150°C) or microwave before serving.
To make ahead, you can bake the cake the day before serving; it actually tastes even better after resting overnight, as the flavors meld. You can also prepare the streusel and dice the apples a few hours ahead (keep apples covered and refrigerated) to speed up assembly.
Nutrition (per serving)
Approximate values per serving (1 of 12, including glaze): 420 calories; 23 g fat; 9 g saturated fat; 52 g carbohydrates; 2 g fiber; 30 g sugars; 6 g protein; 260 mg sodium. These values are estimates and will vary based on specific ingredients and portion sizes.
