Sweet Potato Honeybun Cake

A honeybun cake is the homemade answer to that gas-station honey bun you secretly love, a soft, cinnamon-swirled cake with a sweet glaze poured over the top. This version takes that idea and folds in mashed sweet potato, which is the move that sets it apart. The sweet potato makes the cake remarkably moist and tender, adds a gentle earthy sweetness, and plays perfectly against the warm cinnamon running through the middle.

It’s a true comfort dessert. There’s a ribbon of cinnamon-brown-sugar swirled through the center, the whole thing bakes up soft and golden, and then a vanilla glaze soaks into the warm cake so every bite is sweet and a little gooey. It’s the kind of cake that’s just as at home on a fall dessert table as it is cut into squares for a weekday treat, and it comes together with pantry staples and one bowl of mashed sweet potato.

Why sweet potato makes it better

If you’ve had a regular honeybun cake, you know it can lean a little dry and one-note, all sugar and cinnamon. The sweet potato fixes both problems at once. Mashed sweet potato is full of moisture and natural sugar, so it keeps the crumb soft and damp well past the day it’s baked, and it adds a mellow, almost caramel-like depth underneath the cinnamon. It’s the same reason sweet potato works so well in quick breads and pies.

It also gives the cake that warm color and a tenderness that feels more like a snack cake than a plain sheet cake. You’re not really tasting “sweet potato” in an obvious way, the way you would in a savory dish. It mostly just reads as rich, moist, and a little spiced, which is exactly what you want here.

The two sugars matter too. Using both white and brown sugar in the batter, plus brown sugar in the swirl, builds layers of sweetness with that molasses note from the brown sugar that makes the whole thing taste like a bakery honey bun.

What goes in

this now & bake later ❤️

The cake is a simple oil-based batter, which is part of why it stays so moist. You’ll need all-purpose flour, baking powder, baking soda, salt, and cinnamon for the dry mix, then mashed sweet potatoes, granulated and brown sugar, vegetable oil, eggs, vanilla, and buttermilk for the wet side.

The cinnamon swirl is just brown sugar and cinnamon mixed together and layered into the middle. And the glaze is the classic powdered sugar, milk, and vanilla whisked smooth.

A few notes on ingredients. Use smooth, well-mashed sweet potatoes, with no lumps, or you’ll get pockets of sweet potato in the finished cake. You can roast or boil them and mash, or use canned sweet potato puree (not pie filling) in a pinch. Oil rather than butter is what keeps this cake moist for days, so don’t swap it. And buttermilk adds tang and tenderness, but if you don’t have it, stir a teaspoon of vinegar or lemon juice into regular milk and let it sit five minutes.

How to make it

Heat your oven to 350°F and grease a baking pan. A 9×13 is standard for this cake.

Whisk the flour, baking powder, baking soda, salt, and cinnamon together in one bowl. In a larger bowl, mix the mashed sweet potatoes, both sugars, the oil, eggs, and vanilla until smooth and well combined. Then add the dry ingredients to the wet, alternating with the buttermilk, and mix just until combined. Stop there. Overmixing develops gluten and makes the cake tough instead of tender, so a few streaks are fine to leave until the last gentle stir.

Pour half the batter into the pan and spread it out. Mix the brown sugar and cinnamon for the swirl, and sprinkle it evenly over that first layer. Pour the remaining batter on top, then drag a knife through it in a few S-shapes to swirl the cinnamon layer up into the cake. Don’t overdo the swirling, you want distinct ribbons, not a fully blended cake.

Bake for 35 to 40 minutes, until a toothpick inserted in the center comes out clean. Let the cake cool slightly, just enough that it’s warm rather than hot.

While it cools a little, whisk the powdered sugar, milk, and vanilla into a smooth, pourable glaze. Drizzle it generously over the warm cake. Pouring it while the cake is still warm is the key, the glaze soaks down into the top and into the cracks instead of just sitting on the surface, which is what gives a honeybun cake its signature gooey, glazed top.

Tips and storing

The two things the recipe itself flags are the two that matter most: use smooth mashed sweet potato, and don’t overmix. Both are about texture, and getting them right is the difference between a light, tender cake and a dense one.

A couple more. Glaze the cake while it’s warm but not piping hot, since glaze poured on a too-hot cake just disappears and on a fully cold one just sits on top without soaking in. Warm-but-set is the sweet spot. And if you want a thicker glaze that shows more, use less milk; for a thinner one that soaks in more, add a touch more.

This cake keeps beautifully, which is one of its best qualities. Thanks to the oil and sweet potato, it stays moist for days. Store it covered at room temperature for three to four days, or in the fridge for up to a week. It’s lovely warmed for a few seconds in the microwave, which brings back that just-baked softness. It also freezes well, glazed or unglazed, wrapped tightly, for a couple of months.

This makes a 9×13 cake, around 15 squares. Soft, spiced, swirled, and glazed, it’s pure cozy comfort, the kind of homey cake that tastes like it came from someone’s well-loved family recipe box.

If you want to dress it up, there’s plenty of room to. A handful of chopped toasted pecans folded into the batter or scattered over the glaze adds crunch and suits the sweet potato beautifully. A pinch of nutmeg, ginger, or cloves alongside the cinnamon pushes it toward a spiced, almost pumpkin-pie flavor that’s perfect in fall. And swapping the plain vanilla glaze for a maple or brown-butter one takes it somewhere a little more grown-up if you’re serving it for a holiday.