Ingredients
Equipment
Method
Macerate rhubarb
- Toss diced rhubarb with 1/2 cup sugar and set aside to macerate for 15 minutes, until syrupy and glossy.
Prepare the pan
- Preheat oven to 350°F and grease a 9x13-inch baking pan so the cake releases easily after baking.
Mix wet ingredients
- Cream together softened butter and 1 1/2 cups sugar until light and fluffy, using a thick, pale mixture as the visual cue.
- Beat in the eggs one at a time, then mix in the vanilla extract until smooth.
Mix dry ingredients
- Combine the all-purpose flour, baking soda, and salt in a separate bowl until evenly distributed.
Build the batter
- Add the dry ingredients to the butter mixture alternating with buttermilk, mixing until just combined to keep the crumb tender.
- Fold in the sugared rhubarb, then pour the batter into the prepared pan and smooth the top.
Bake
- Bake at 350°F for 40-45 minutes, until a toothpick inserted in the center comes out clean.
Cool and finish
- Cool completely for 30 minutes before dusting with powdered sugar so the topping clings lightly.
- Dust with powdered sugar and serve at room temperature, with visible pink rhubarb pieces throughout the slices.
Notes
For the best texture, mix the batter only until the dry ingredients disappear—overmixing can make the crumb tough. Store covered in the refrigerator up to 4 days; re-dust with a light pinch of powdered sugar if you want a fresh look. Freezing is yes: wrap slices well and freeze up to 2 months. For a dairy swap, use an equal amount of plain yogurt or kefir in place of buttermilk for similar tang and moisture.