Vegan Cinnamon Coffee Cake Recipes With Flax Egg and Oat Milk: Bakery Crumb at Home
Get a tender, cinnamon-swirled crumb cake with a crunchy topping, using pantry staples and dairy-free swaps that actually work.
You want coffee cake energy without the “why is this dry?” betrayal. You want that thick cinnamon ribbon and a crumb topping that rains down like delicious chaos. And you want it vegan, but still bakery-level, not “health project in a pan.” Good news: flax egg + oat milk isn’t a compromise, it’s the cheat code. Make this once and you’ll start offering people “just a slice” like you don’t know what happens next.
What Makes This Recipe So Good
Flax egg brings binding power and a slightly plush crumb, so slices hold together instead of crumbling into sad gravel. It also keeps the batter forgiving, which matters when your “measuring cup” is vibes.
Oat milk gives gentle sweetness and body, plus it plays nicely with cinnamon and brown sugar. IMO it makes the cake taste more “cozy” than some other plant milks that can read watery or overly nutty.
The cinnamon swirl adds contrast and that signature coffee-cake moment: vanilla cake, warm spice, then a little caramel note from brown sugar. It’s basically a plot twist you can eat.
The crumb topping uses a simple ratio that bakes up crisp on top but stays sandy and buttery underneath. Translation: you get both crunch and melt, because why choose?
Shopping List – Ingredients
- Ground flaxseed: 2 tablespoons
- Warm water: 5 tablespoons
- All-purpose flour: 2 cups
- Baking powder: 2 teaspoons
- Baking soda: 1/2 teaspoon
- Fine salt: 1/2 teaspoon
- Ground cinnamon: 2 1/2 teaspoons, divided
- Light brown sugar: 3/4 cup, packed, divided
- Granulated sugar: 1/3 cup
- Unsweetened oat milk: 1 cup
- Apple cider vinegar or lemon juice: 1 tablespoon
- Neutral oil (canola, avocado, grapeseed): 1/2 cup
- Vanilla extract: 2 teaspoons
- Vegan butter (or solid coconut oil): 6 tablespoons, softened
- Optional chopped walnuts or pecans: 1/2 cup
- Optional powdered sugar: for a light finish
The Method – Instructions
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Prep the pan and oven. Heat oven to 350°F. Grease an 8×8-inch pan and line with parchment, leaving a little overhang for easy lifting.
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Make the flax egg. Stir ground flaxseed with warm water until it looks gel-like. Let it sit 8 to 10 minutes so it thickens properly.
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Make “buttermilk.” Mix oat milk with vinegar (or lemon juice). Let it sit 5 minutes; it should look slightly curdled, which is the whole point.
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Mix the dry base. In a large bowl, whisk flour, baking powder, baking soda, salt, and 1 teaspoon cinnamon. Whisking now prevents surprise bitter pockets later.
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Build the wet mix. In a second bowl, whisk oil, granulated sugar, 1/4 cup brown sugar, vanilla, the flax egg, and the oat “buttermilk” until smooth.
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Combine gently. Pour wet into dry and stir just until you stop seeing flour streaks. Don’t “beat it into submission” unless you want a tough cake.
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Make the cinnamon swirl. In a small bowl, mix 1/2 cup brown sugar with 1 1/2 teaspoons cinnamon. If your brown sugar is clumpy, break it up with your fingers.
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Make the crumb topping. In another bowl, mix flour (3/4 cup), remaining 2 tablespoons brown sugar, remaining 1/2 teaspoon cinnamon, and a pinch of salt. Cut in softened vegan butter until you get chunky crumbs. Stir in nuts if using.
Note: The topping should hold together when squeezed, then fall apart. If it’s dusty, add 1 more tablespoon vegan butter; if it’s greasy, add 1 to 2 tablespoons flour.
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Layer like you mean it. Spread half the batter in the pan. Sprinkle the cinnamon swirl evenly. Spoon the remaining batter on top and gently spread to cover.
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Top it off. Scatter the crumb topping all over, including the corners. Yes, use it all. This is coffee cake, not a restraint exercise.
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Bake. Bake 35 to 45 minutes, until the center springs back and a toothpick comes out with a few moist crumbs (not wet batter). If the top browns too fast, tent loosely with foil.
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Cool before slicing. Let it cool in the pan 20 to 30 minutes. Cut too early and it’ll steam itself into a gummy situation. Patience, chef.
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Finish (optional). Dust lightly with powdered sugar once cool. It’s not required, but it does make it look like you bought it “from a place.”
How to Store
Room temperature: Store covered for up to 2 days. Keep it in the pan or in an airtight container so the crumb topping stays crisp-ish.
Fridge: For 4 to 5 days, refrigerate slices in an airtight container. The crumb softens a bit, but the flavor deepens, so it’s a fair trade.
Freezer: Wrap individual slices tightly and freeze up to 2 months. Thaw at room temp, then warm briefly to revive that fresh-baked vibe.
Reheat tip: Microwave 10 to 15 seconds for softness, or use a toaster oven for 3 to 5 minutes to re-crisp the topping.
What’s Great About This
This recipe hits the big three: soft crumb, bold cinnamon, and crumb topping drama. It tastes like a weekend treat but doesn’t require a weekend to make.
It also scales with your life. Hosting brunch? Bake it as-is and watch it disappear. Just you? Freeze slices and become your own favorite cafe.
And yes, it’s vegan without announcing itself. Nobody bites in and goes, “Wait… is this made of sadness?” It’s just good cake.
What Not to Do
- Don’t rush the flax egg. If it’s watery, it won’t bind as well and the cake can bake up fragile.
- Don’t overmix the batter. Overmixing builds gluten and turns tender cake into a chewy “bread situation.”
- Don’t skip the acid in the oat milk. Vinegar/lemon helps lift the cake and balances sweetness. You won’t taste it, promise.
- Don’t press the crumb topping flat. You want peaks and crags for maximum crunch and those golden edges.
- Don’t cut it piping hot. The swirl needs time to set; slicing too soon makes the center slump.
Variations You Can Try
Maple crunch version: Replace 2 tablespoons of the brown sugar in the topping with maple sugar, or add 1 tablespoon maple syrup and 1 to 2 tablespoons extra flour to keep crumbs crumbly.
Apple cinnamon coffee cake: Fold 1 cup small-diced apples (peeled) into the batter. Add 1 extra tablespoon flour to the batter to offset the moisture.
Mocha swirl: Add 2 teaspoons instant espresso powder to the cinnamon swirl mixture. It reads like a bakery “limited edition,” FYI.
Glaze finish: Whisk 3/4 cup powdered sugar with 1 to 2 tablespoons oat milk and a splash of vanilla, then drizzle once cooled.
Muffin mode: Bake in a lined muffin tin for 18 to 22 minutes. Add swirl and topping the same way; it’s messy in the best way.
FAQ
Can I use another plant milk besides oat milk?
Yes. Almond and soy both work well. Choose unsweetened to control sweetness, and still add the vinegar or lemon juice for the lift and balance.
How do I make a flax egg if I only have whole flax?
Grind it first (spice grinder or blender). Whole flax won’t gel the same way, and you’ll end up with crunchy seeds instead of a proper binder.
Why did my crumb topping melt into the cake?
Your fat may have been too soft or you needed a touch more flour. Next time, keep the vegan butter softened but not oily, and aim for chunky crumbs that hold shape when pinched.
Can I make this oil-free?
You can swap the oil for 1/2 cup unsweetened applesauce, but expect a slightly denser, more muffin-like texture. It’ll still taste great, just less “bakery rich.”
What pan sizes work if I don’t have an 8×8?
A 9×9 makes a slightly thinner cake and bakes faster, so start checking at 28 to 32 minutes. A 9-inch round works too; watch the center for doneness.
How do I know it’s baked without drying it out?
Look for a set center and a toothpick with moist crumbs, not wet batter. If you wait for a totally clean toothpick, you can overshoot and lose that tender bite.
Wrapping Up
This is the kind of cake that makes people “casually” wander into your kitchen and hover. It’s soft, cinnamon-forward, and topped with crumbs that act like they pay rent.
Use the flax egg and oat milk exactly as written, and you’ll get a reliable rise and a sliceable crumb every time. Then tweak the swirl, add nuts, drizzle glaze, or keep it classic.
Now make it, pour the coffee, and pretend you’re the type of person who just has coffee cake lying around. Nobody needs to know the truth.
