Rhubarb Cake

Bake a moist Rhubarb Cake with diced rhubarb and a crunchy sugar topping - easy and crowd-pleasing.

Ingredients

• 1½ cups (300 g) brown sugar, (packed)
• ⅔ cup (145 g) vegetable oil
• 2 large eggs, (room temperature)
• 1 cup (245 g) buttermilk
• 1 teaspoon kosher salt
• 1 teaspoon baking soda
• 1 teaspoon vanilla
• 2½ cups (312.5 g) all-purpose flour
• 3 cups rhubarb, (diced)
• ¼ cup (50 g) granulated sugar

Instructions

Step 1: Preheat and Prepare the Pan

Preheat the oven to 350°F and prepare a 9x13‑inch baking dish by spraying it evenly with nonstick cooking spray so the surface is lightly sheened. While the oven comes up to temperature, keep your workspace clear on the painted pine surface and set the empty rectangular pan nearby; this simple prep keeps the final geometry consistent and makes the next steps smoother.

Step 2: Whisk the Wet Ingredients Together

In a large mixing bowl, whisk together the brown sugar, vegetable oil, eggs, buttermilk, kosher salt, baking soda, and vanilla until the mixture is homogenous, glossy, and slightly aerated. You want a thick, cohesive wet base with tiny pockets of air from the whisking — this is the moment the batter’s structure starts to form and determines the cake’s moist, dense crumb.

Step 3: Fold in Dry Ingredients and Rhubarb, Pour into Pan

Gently stir the all‑purpose flour into the wet mixture until just combined, taking care not to overwork the batter; it should be thick, ribboning slightly from the spatula. Fold in the diced rhubarb so bright pink and ruby pieces are distributed through the batter, then scrape the batter into the prepared rectangular baking dish so the surface is level. Lightly sprinkle the top with granulated sugar for a faint crunchy finish before baking.

Step 4: Bake, Rest, and Serve

Bake until the top is golden-brown and a toothpick inserted into the center comes out clean, then let the cake rest in the pan for about 30 minutes to set; the edges should be slightly crisp while the interior remains tender and moist with visible pockets of rosy rhubarb. When ready to present, cut a rectangular slice that preserves the baked pan’s geometry; serve warm or at room temperature, optionally with a small scoop of vanilla ice cream or whipped topping.

Notes

• Use room temperature eggs for better emulsion and even baking.
• If using frozen rhubarb, thaw and drain well to prevent extra moisture.
• Lightly dust slices with powdered sugar or serve with vanilla ice cream for extra appeal.
• For a dairy-free version, use plant-based milk plus vinegar as buttermilk substitute.