Cinna-bun Cake — Oven-Baked Cinnamon-Roll Sheet Cake
Every bite of this Cinna-bun Cake tastes like a warm hug from the past: swirls of buttery cinnamon, a brown-sugar streusel that melts into the batter, and a glossy vanilla glaze poured over the top. It’s the easiest way to bring the cozy, gooey satisfaction of a cinnamon roll to a sheet pan — perfect for brunches, potlucks, holiday mornings, or whenever you need a comforting centerpiece dessert.
Why this recipe is irresistible
This cake returns the familiar riffs of a classic cinnamon roll — rich butter, dark brown sugar, and warm cinnamon — but simplifies them into a single cake you can slice and serve. The cake base stays tender and slightly cakey while the topping sinks in during baking to create ribbons of caramelized cinnamon. Finish with a sweet, vanilla glaze and you have the sticky, aromatic dessert everyone reaches for first.
Ingredients (and what each one does)
Use full-fat ingredients when possible for the richest flavor and best texture.
- 3 cups (360 g) all-purpose flour — the structure of the cake. Measured by spooning into the cup and leveling for accuracy.
- 1 cup (200 g) granulated sugar — sweetens and helps form a tender crumb.
- 1 tablespoon baking powder — leavening agent that gives the cake lift and lightness.
- 1½ cups (360 ml) milk — hydrates the batter and adds tenderness; whole milk adds extra richness.
- 2 large eggs — bind and provide structure, promote browning.
- 8 tbsp (112 g) unsalted butter, melted — fat for richness, flavor, and a buttery mouthfeel; part of it enriches the cake, part is used in the topping.
- 1 tsp vanilla extract — aromatic lift that rounds all the flavors.
For the topping (the “cinnamon bun” swirl)
- 1 cup (220 g) unsalted butter, softened — creates the luxurious ribbon of butteriness and helps the brown sugar melt into pockets.
- 1 cup (220 g) packed brown sugar — molasses-rich sweetness that caramelizes and gives that iconic cinnamon-bun flavor.
- 3 tbsp all-purpose flour — binds the topping and gives it a slightly cakier texture so it swirls nicely into the batter.
- 3 tsp ground cinnamon — the aromatic star of the show; adjust to taste if you prefer more or less spice.
For the glaze
- 2 cups powdered sugar — silky sweetness and glossy finish.
- ⅓ cup milk — thins the glaze to a pourable consistency; use a little less for a thicker drizzle.
- 1 tsp vanilla extract — balances the powdered sugar and echoes the cake’s vanilla.
Step-by-Step Instructions
- Preheat and prep: Preheat the oven to 350°F (175°C). Grease a 9×13″ baking dish with butter or nonstick spray and set aside.
- Make the cake batter: In a large bowl whisk together the flour, granulated sugar, and baking powder until evenly combined. In a separate bowl, whisk the milk, eggs, melted butter (cooled slightly), and vanilla until smooth. Pour the wet ingredients into the dry and stir gently until just combined — a few small streaks are fine. Overmixing will make the cake tough.
- Spread the batter: Pour the batter into the prepared pan and smooth the top with an offset spatula so it’s evenly distributed.
- Prepare the cinnamon topping: In a medium bowl beat the softened butter, brown sugar, flour, and cinnamon with a hand mixer or sturdy spoon until smooth and spreadable. The mixture should hold together but still be soft enough to drop by spoonfuls.
- Drop and swirl: Drop spoonfuls of the topping across the surface of the cake batter. Aim for even coverage — leave a few gaps so the cake batter peeks through. Using a butter knife or skewer, drag the topping through the batter with gentle swirls; don’t over-mix — you want marbled ribbons, not full incorporation.
- Bake: Bake 40–45 minutes, or until a toothpick inserted in the center comes out mostly clean with a few moist crumbs (the brown sugar pockets may be gooey — that’s desirable). If the top browns too quickly, tent with foil for the last 10 minutes.
- Cool slightly: Remove the pan from the oven and allow to cool 10–15 minutes so the topping sets slightly and the glaze won’t melt off completely.
- Make the glaze & finish: Whisk the powdered sugar, milk, and vanilla until smooth. Pour or drizzle the glaze over the warm cake, spreading gently if needed. Allow the glaze to set for 15–20 minutes before slicing into squares.
Why this technique works
The cake base provides a tender, slightly tender crumb that accepts pockets of melted brown sugar and butter. Dropping the topping and swirling it — rather than layering it thickly — creates varied textures: soft cake, caramelized pockets, and a top that crisps just slightly. Keeping the glaze pourable but not watery ensures a sweet sheen that doesn’t soak the cake.
Pro Tips for Perfect Cinna-bun Cake
- Room-temperature eggs and milk: They emulsify better with melted butter and give a uniform batter.
- Don’t overmix: Stir until the dry ingredients are moistened; overworking develops gluten and yields a denser cake.
- Even topping distribution: Drop topping in dollops instead of smearing; swirl just enough to create ribbons.
- Watch your bake time: Because of the sugar pockets, the cake may look slightly moist in the center — test with a toothpick and trust that a few moist crumbs are fine.
- Make ahead: Bake the cake, cover tightly, and keep at room temperature for up to 24 hours. Glaze just before serving for the freshest finish.
- Prevent soggy bottoms: Use a light, even layer of batter and do not overpour glaze; allow the cake to cool slightly before glazing.
Variations & Flavor Twists
- Apple Cinna-bun Cake: Fold 1½ cups peeled diced apples (tossed in 1 tbsp lemon) into the batter for autumnal warmth.
- Pecan Crunch: Stir 1 cup chopped toasted pecans into the topping for added texture and nuttiness.
- Maple Glaze: Replace half the milk in the glaze with pure maple syrup for deeper flavor.
- Chocolate-Cinnamon: Add 1/3 cup cocoa to the batter and swap half the brown sugar for a chocolatey twist.
Serving Suggestions
Serve warm by the square, either plain or with a scoop of vanilla ice cream for dessert. For brunch, pair slices with whipped cream, fresh berries, or a drizzle of warm caramel. This cake also pairs beautifully with coffee, spiced chai, or a milky latte.
Storage & Make-Ahead
Room temp: Store covered at room temperature for up to 24 hours. Refrigerate: For longer storage, cover and refrigerate up to 4 days (bring to room temperature or warm gently before serving). Freeze: Freeze unglazed slices wrapped tightly for up to 2 months; thaw overnight in the fridge and glaze before serving.
Final Word — Simple, Nostalgic, and Crowd-Pleasing
This Cinna-bun Cake is proof that the best desserts don’t need to be complicated. With a straightforward batter, a buttery brown-sugar topping, and a shiny vanilla glaze, it captures the spirit of the classic cinnamon roll in an easy, sliceable format. Whether you’re feeding a brunch crowd or craving a comforting treat, this cake offers warm aroma, sticky pockets of caramel, and a familiar sweetness that feels like home. Try it once — and you’ll have a new favorite to bake again and again.
