Easy Rhubarb Breakfast Cake

A moist, tender cake speckled with sweet-tart rhubarb, finished with a lightly crunchy sugar crust—the kind of comforting, homey dessert that tastes like grandma used to make.

Why I’ll Love This Recipe

I adore how the tart rhubarb contrasts with the light vanilla-scented cake, and that sugary crust adds a delightful crunch. It’s versatile enough for breakfast, snacks, or dessert, and I’ve found it always disappears fast—warm or cold.

ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

• ½ cup half-and-half (or cream or buttermilk)

• 1 teaspoon lemon juice

• ½ cup unsalted butter, room temperature

• 1 cup granulated sugar + 2 tsp for sprinkling

• 1 large egg, room temperature

• 1½ tsp vanilla extract

• 2 cups all-purpose flour (reserve 1 Tbsp)

• 2 tsp baking powder

• 1 tsp salt

• 2 cups thinly sliced rhubarb

directions

1. Preheat oven to 350°F and lightly butter a 9″×9″ pan (I often line it with parchment for easy removal).

2. Stir lemon juice into half-and-half; set aside.

3. Cream butter and sugar until pale, then beat in egg and vanilla, scraping sides.

4. Toss rhubarb with reserved flour tablespoon.

5. Whisk together remaining flour, baking powder, and salt.

6. Add half the flour mixture to batter, blend, then add half-and-half, then remaining flour—mix just until combined. Fold in rhubarb; the batter will be thick.

7. Spread batter in pan, sprinkle top with 2 tsp sugar.

8. Bake 40–45 minutes, until golden and a toothpick comes out clean (moist crumbs okay).

9. Cool slightly, slice, and enjoy.

Servings and timing

Makes 12 squares
Prep time: ~15 minutes
Bake time: 40–45 minutes
Total time: ~1 hour

Variations

• Toss in berries (e.g., blueberries, strawberries) or banana instead of rhubarb.

• Sprinkle the sugar topping with cinnamon, or mix a bit of almond extract into the batter.

• For a lighter version, use buttermilk (or half Greek yogurt + milk) instead of half-and-half; omit lemon juice if using buttermilk.

storage/reheating

I store leftovers in an airtight container at room temperature for up to 2 days, or refrigerate for up to 4 days. To reheat, I pop a slice in the microwave for about 10–15 seconds (it’s delicious warmed) or heat gently in a 300°F oven for 5–7 minutes to restore the crisp top. If freezing, I wrap individual slices tightly and freeze for up to 2 months—thaw overnight in the fridge before serving.

FAQs

What other fruits can I use in this cake?

I’ve swapped in berries or chopped banana—almost any fruit like diced apple or peaches work wonderfully.

Can I substitute frozen rhubarb?

Yes! I use frozen sliced rhubarb straight from the freezer—there’s no need to thaw it, which helps avoid sogginess.

Why does it call for lemon juice?

It brightens the flavor of the half-and-half and enhances the tartness of the rhubarb, balancing the sweetness. If I use buttermilk, I skip the lemon juice.

How do I prevent a soggy cake?

It’s key to slice the rhubarb thinly and toss it with a little flour before folding into the batter. That coating helps absorb excess moisture.

Is this suitable for gluten-free diets?

I haven’t tested it myself, but a gluten-free all-purpose flour blend with a bit of xanthan gum should work as a substitute.

Conclusion

I love this Rhubarb Breakfast Cake for its simplicity, versatility, and nostalgic comfort. Tart rhubarb, vanilla-kissed batter, and that sweet-crunchy crust make every slice irresistible. I hope you enjoy baking and devouring it as much as I do!